I 'd recommend you to go with Inquisition at 1k points game with a list like this:
Hq:
Coteaz (Divination) 100
Elites:
Techmarine w/ Rad Grenades + Psychotroke Grenades + Power weapon (your choice) + 1x Servo Skull 118
Vindicare Assassin 145 (in a bolster ruin)
Troops:
1st Inquisitorial Henchmen Squad : (10) 3x Plasma Cannon Servitors + 3x Plasma Gun Acolytes + 4x Crusaders w/Power Axe 162 (Coteaz here)
2nd Inquisitorial Henchmen Squad : (11) 7x Death Cult Assassins w/ Power sword + Power Axe + 4x Crusaders w/Power Axe 165 (Techmarine here)
3rd Inquisitorial Henchmen Squad : (3) Acolytes w/ Bolters in a Rhino 55
Fast
Atk:
Stormraven w/
TL Assault Cannon +
TL Multi-Melta + Hurricane Bolters + Psybolts 255 (2nd Inquisitorial Henchmen Squad + Techmarine here)
On the other hand that's just me .. So if you want
GK exclusively then I suggest something like this :
Hq:
Librarian (Bare Bones but with Divination) 150
Troops:
5x
GKSS w/ 1x Psycannon + 2x
NFS +1x
NFH (Justicar) + 1
NDH 125 ( can also
DS )
10x GKT w/ 2x Psycannons + 4x
NFS + 4x
NFH (Justicar) + 2x
NDH + Psybolts 470 ( Combat Squad and Psycannons go with Libby the others
DS )
Fast
Atk:
Stormraven w/
TL Assault Cannon +
TL Multi-Melta + Hurricane Bolters + Psybolts 255
I couldn't find where to spend 15 points so that's why the
GKSS has so many upgrades ( which they don't wort em

)