From how I read the talents, to take Signature Wargear (Master), which allows you to get an item of Requisition 40 or less, you have to first have Signature Wargear for the same item .

The Power Fist costs 35 Requisition. This means that you cannot take it as Signature Wargear (normal-which only covers requisition of 20 or less). This means that you can't get it as a Signature Wargear (Master) item, as you can't meet the requirement.

Thus, the only way you can get it as Signature Wargear is to take it as your single slot of Signature Wargear (Hero), at which point you can spend 70 points of Requisition, and might as well get a Master-crafted Power Fist.

Is this correct?

If this is correct, can any of the Developers chime in on the rationale? I have trouble understanding why a Master-crafter Power Sword is acceptable as Signature Wargear (Master) and a Power Fist isn't.

The Power Sword would be Master-crafted, so it would give +10% Weapon Skill, and +2 damage, and it could also give an additional +10% weapon skill (from the options for Signature Wargear (Master)). A Power Weapon that does 1d10+8 damage with a penetration of 6, and which adds +20% to hit and +30% to Parry (since it is Balanced, too), seems much better than a Power Weapon which does 2d10 + (3xSB) with Penetration 9, and no bonus to hit (and no parries possible). Especially when you add the extra attacks from things like Counter Attack, and the rerolls from Sword Master.

It also doesn't seem unrealistic in the universe for a Marine to be equipped with a Power Fist (or a Storm Shield, or a Lightning Claw) as a signature piece of Wargear, but by the rules, the only people toting those around are Heroes of the Imperium with Master-crafted ones, while any well-respected Space Marine can get their hands on a Master-crafted Power Sword.

Not quite. You do need to take Signature Wargear as a prereq to the Master version. However, the Master talent allows you to replace your signature wargear or improve the one you have. So, for the basic Signature wargear you could take a Master chainsword or a basic power sword. Then take a basic power fist for the Master talent.

It is unfortunate that you can't combine signature wargear talents. The Req limit does prevent you from getting a lot of gear, especially exceptional/master crafted items. I'd probably house rule that if you pick up a second Signature talent (beyond Master), you could apply that as an improvement to your existing master item (say improving your power fist to Exceptional, or adding a Suspensor to your Exceptional Heavy bolter).

Blargl...double post.

Houserule

-Signature Wargear-
1) 25 XP per requisition point of the base item.

2) 25 XP per requisition point in modifications (including exceptional and master quality).

2a) Exceptional quality Wargear increases the requisition cost by 5-requisition per rank (Initiated [5], Respected [10], Distinguished [15], Famed [20] and Hero [25]).

2b) Master quality Wargear increases the requisition cost by 10-requisition per rank (Initiated [10], Respected [20], Distinguished [30], Famed [40] and Hero [50]).

3) Limitations

3a) Signature Wargear is limited to a maximum of 15-points of modifications. Renown requirements for Exceptional Wargear are waved.

3b) Signature Wargear (Master) is limited to a maximum of 35-points of modifications. Renown requirements for Master Wargear are waved. The experience spent on Signature Wargear (Master) replaces that of the experience spent on Signature Wargear (the difference is paid).

3c) Signature Wargear (Hero) is limited to a maximum of 65-points of modifications. Renown requirements for Hero Wargear are waved. The experience spent on Signature Wargear (Hero) replaces that of the experience spent on Signature Wargear (Master) (the difference is paid).