Reading the rules of the Gank from "Lords from Nal Hutta", i got some idea for Droidmodifications.
Droids right now are very "unrestricted", which is fun, but one thing i missed were excessive droid modifications.
I'm not talking of upgrading a droid to a combat or slicing master, but if you think of r2-d2 he is full of stuff like tools and fireextingusher and other stuff, but he can not talk proberly.
Enough of my bad english, here are some ideas:

PC Droid starts with only 125 points but 5000 credits of Droid/Bionik Stuff and 10 Hardpoints instead of 6

Basics for a Droid:

Vocabulator: 1000Cr, 1HP, Rarity: 6
Droids are able to speak, or could be used as replacement (Darth Malak)

Arms: each 1000Cr, 1HP, Rarity: 6
Without arms, a droid has an encumbrance treshold of Brawn+1, for each additonal arm the droid gets +2

Legs or Wheels: Free
or
Repulsorunit: see Jetpack, 2HPs
The droid can fly, counts as jetpack

Light Casing: Soak 1 Free
or
Heavy Duty Casing: Soak 2, free, 1HP
or
Military Casing: Soak 3, 2500Credits, 2HP, Rarity:8 restricted

Build in Tools:

Tools: 3500 Cr, 4HP, Rarity 6

build in Toolkit

Medical: 4000 Cr, 4HP, Rarity 6

build in Medkit including StimInjector

StimInjector: 500 Cr, 1HP, Rarity 6

one use per session, 1 build in Stimpack

Cyberbrain Upgrades:

TransLang III communications module: 3000 Cr, 1HP, Rarity 8

Fluency in 6 million forms of communication: Get 1 Boost Die for Knowledge:Xenology

AA1 VerboBrain: 5000 Cr, 1HP, Rarity 8
Remove one Setback Die on any Negotiation or Charm test

MDF Motivator: 5000 Cr restricted, 1HP, Rarity 8

Remove one Setback Die on any Coercion or Discipline test

First off, what kind of droid are you representing in your post? Secondly, I think you have recreated some items that are already represented in equipment through out all of the books, and that is why I asked what kind of droid.

Military grade casing = armor implant is 7500, arms anywhere between 2000 = repli limbs and 10000 = cybernetic limbs depending on the type of droid (an astromech like chopper would have different smaller possibly cheaper arms), brain implant is 10000. You wouldn't be able to put a full tool kit into a astromech droid or any other droid due to limited space in said droid, and there are tools that can be installed in them like arc welder and hydrospanner. Enc still comes into play.

I do believe there are rules that govern these attachments/mods that are in the books except for some items that you have created.

Don't get me wrong, I like what you have done except for the prices and what is in the books. There was a discussion in these forums about the limbs, armor and brain upgrades along with modifications for droids also.

So… a droid with two arms would have Brawn: 5?

Threepio, you've been holding out on us!

Repli limbs don't give characteristics boosts, again what kind of droid you are building depends on what you take. A Maurader droid could potintialy have a brawn of 6 but not much else.

Reading the rules of the Gank from "Lords from Nal Hutta", i got some idea for Droidmodifications.

Droids right now are very "unrestricted", which is fun, but one thing i missed were excessive droid modifications.

I'm not talking of upgrading a droid to a combat or slicing master, but if you think of r2-d2 he is full of stuff like tools and fireextingusher and other stuff, but he can not talk proberly.

Enough of my bad english, here are some ideas:

Not sure what you are trying to resolve with this. First, NPCs aren't built like PCs. XP requirements don't matter, having a Career/Specialization isn't part of them. As for gear in the droid, I've just generally given the PC what seemed reasonable for the base model of what they wanted to play. Any other gear required the PC to buy it as normal.

My intention was a differnt kind of "race" for the droid, which reflects the physical differences of the different models.

Threepio has two arms, legs, a vocabulator, light casing, Verbobrain and Translang III module (5Hardpoints)

-> EncumberanceTreshold of Brawn+5 (like a human), able to speak regular, Boost for social stuff

R2D2 has no arms, wheels (maybe like hutt movement?), no vocabulator, light casing, Tools, fire-extinguisher, Holoprojector and other stuff (6+ Hardpoints)

-> EncumberanceTreshold of Brawn+1 (less than a human), not able to speak reguar, Build in Tools

Imperial probe droid has no arms, repulsor unit, no vocabulator, high duty casing, Sensors (Tools),military comunicator and build in Weapon (10 Hardpoints)

-> EncumberanceTreshold of Brawn+1 (less than a human), not able to speak regular, Build in Senors, Flying,...

I hope you get the idea. Intention as inspiration for someone with better english skills

I am sorry but, by the rules a droid PC cannot go over 6 Cybernetic implant cap, see page 47 of Egde of the Empire, Droids, Special abilities. Cybernetic implants are the "hardpoints" for PCs.

Now NPCs, you can go as crazy as you want.

I like some of the concept of the original poster, but am not sure his English was up to the task of explaining what he wanted. I have been having a problem for a while with just how customizable the droids are, and have been considering some changes myself.

Effectively he wants to create sub-races of droids, so when a player says he wants to play an R2 unit, he picks R2 as a "race" instead of "droid". So each model of droid has its own "race" stats. That prevents some of the odd customizations I could imagine.

I see the current droid rules as a framework to build the droid races. We just need to stat out the special effects.

I like some of the concept of the original poster, but am not sure his English was up to the task of explaining what he wanted. I have been having a problem for a while with just how customizable the droids are, and have been considering some changes myself.

Effectively he wants to create sub-races of droids, so when a player says he wants to play an R2 unit, he picks R2 as a "race" instead of "droid". So each model of droid has its own "race" stats. That prevents some of the odd customizations I could imagine.

I see the current droid rules as a framework to build the droid races. We just need to stat out the special effects.

I can see what you are saying, you can swap components all you want but, RAW states droids do not get more than 6 cyber implant slots. Can RAW be house ruled? Yep, but, ultimately, 6 implants total,. to include sub races of droids. unless it states it another book.

less starting XP, more "implants"
like the Ganks from "Lords of Nal Hutta"

if arms, legs and vocalizer are count as implant (not any droid have them), 6 implants is not so much

Ganks are not droids, and have a culture of cybernetics. Humans and Ganks both start with 110xp for building, and have the fewest limitations. Droids are specialized in what they do and that is why the rules say 6 implants maximum. You shouldn't go over 6 in any characteristic (5 on Character build) or 7 with cybernetics.

I just stated what the rules state but you can do what you would like as they are only a guide. Just be sure that you don't overpower the characters to where they beat everything easily.

This may help

https://community.fantasyflightgames.com/index.php?/topic/174645-droid-pcs/#entry1599674