Hey guys, I started to update the guide again, hope it will help you further.
Unique armor is sometimes not that great, I agree, did my first run with this build with tailoring as well, I realized it might not be needed and did a second run without, and it went well. But, yeah, tailoring is still a very good choice, but you have to sacrifice some skills to get it.
12.7mm sniper, yes. Corsair or Harbringer, there is theoretical pro and cons with them, but tbh ... hard to feel difference, so I just went with best quality frame (It was a Corsair one), maybe Corsair is a bit better if you get gun nut, as you upgrade an already bigger upper damage.
the main issue is to get the Bolt Quiver wich is an essential part in the 36AP + 14AP = 50AP equation.