Grey Knight character building

So i am creating my own special grey knight character based of a tech marine.
Last night i was looking at 2 tech marines i had never put together and their servitors, thinking to myself hmm i should glue these fuckers together. well then i noticed my cutters and a couple spare heavy bolters, and the conversion started(I will post pics when its painted). so a few sprues later and i had one customized techmarine sporting 2 heavy bolters, a flamer, a plasma cutter, and 2 storm bolters.
Well then i was like wtf am i going to do with this guy, well i did want a tech marine for my grey knights, but they dont have one in their codex. So i decided well someone has to manufacture all of those special grey night bullets and take care of their guns, so the Gunsmith was born.

What i need help with is a balanced stat line, gear, special rules, points, etc. here is what i have so far. The stuff below is based off a standard techmarine and with additional points explained. So what do you all think?

Code:

Name     Points   WS   BS   S   T   W   I   A   Ld   Sv
Gunsmith 155     4     4    4   4   2   4   1    9   2/5+
      2 storm bolter, twin-linked Psycannons, 2 Incinerator, Artificer armor, frag and krak grenades, psycannon bolts, refractor field                        
      Grey Knight rules, blessing of the omnissah                        
                              
      50 standard techmarine includes 1 storm bolter artificer armor and grenades   
      30 first psycannon +15 for twinlinked                  
      15 pts incinerator x2                        
      10 extra storm bolter                        
      10 psycannon bolts                        
      20 points refractor field   

The point cost on the psycannon bolts, refractor field and storm bolter may be wrong i did not havea codex with me to get their point cost.

during the shooting phase i figure he should be able to shoot with either the psycannon and storm bolters OR the incinerators

I have not added extra points for the additional wound he has but thought his cost was high enough as is. I think he should be fielded with an additional retinue of 5 servitors(required) at an additional 70 points that are equipped with servo arms.

Since he has traded all of his servo arms for weapons the only way he can repair is with the servitors(this is way they must be equipped with servo arms and not other weapons).

What do you guys think? please consult your codexs and offer feed back on points adjustments and eq changes.