I know some people were disappointed with the lack of options for playing Techmarines. Since I like Techmarines myself, and since I'm a fan of Iron Warriors, here's what I came up with:
Techmarine Training
Unaligned
Tier 1
Prerequisites: Chaos Space Marine, Champion or Forsaken, Tech Use, Int 40, WP 40, Can only be taken at character creation, One of starting Acquisitions must be spent on a Cybernetic (either a bionic limb or an implant system) of at least Good Craftsmanship.
The character may be a renegade Techmarine, or perhaps even one of the infamous Warsmiths of the Iron Warriors legion. Either way, he has undergone special training and additional implantation, granting him higher understanding of technology and access to best cybernetics.
Although the character doesn't receive the benefits of the Mechanicus Implants Trait, he is treated as if he possessed it for the purpose of meeting Talents' prerequisites. Furthermore, he is treated as a Heretek for the purpose of cybernetics' Availability.
So, how does that sound? I'm not sure about the second part, considering it's a Tier 1 Talent, but I want to keep it Tier 1 so it can be purchased at character creation.