1250pts tournament. Grey Knights or Imperial Guard?

I've made 4 different lists. The IG one is fully painted (my Death Korps) the GK needs everything GKy to have a lick of red paint (Pre-heresy Thousand Sons).

I have about 3 weeks, but there is no painting score, everything just needs to be painted. The tournament is played on 48x48" tables, which is why I opted for some terminators mainly.

Last time I played the first GKlist and came in third. It worked really well. Last game I failed against 9 Hive Guards and 3 Tervigons because I wasn't offensive enough with the Purifiers. I really like to play mechy gun lines with one offensive element (Straken command squad etc, mech BA with Mephiston). Any thoughts from the internet?

Grey Knights #1 1250

Coteaz 100

Purifier Squad (7) 199 - Rhino 40
-2 Psycannons, 1 Daemonhammer, 3 Halberds

5 SBwarriors 35 - Chimera (ML, HF)
5 SBwarriors 35 - Chimera (ML, HF)
4 Warriors 3 w. Melta – Chimera (ML, HF)
4 Warriors 3 w. Melta – Chimera (ML, HF)
3 Warriors 12 - Psyback
3 Warriors 12 - Psyback

3x Psyflemen

Coteaz rides with the Purifiers. Quite straightforward.

Grey Knights #2 1250

Coteaz

5 Paladins
-Psycannon, Hammer
-Psycannon, Halberd
-Sword
-Halberd
-Halberd

5 SBwarriors - Chimera (ML, HF)
5 SBwarriors - Chimera (ML, HF)
3 Warriors - Psyback
3 Warriors - Psyback
3 Warriors - Psyback
3 Warriors - Psyback

3x Psyflemen

Paladins provide counter-charge together with Coteaz and can threaten other shooty armies as they wade through cover and shoot 8 Str7 rending shots. No melta at all might be a problematic.

Grey Knights #3 1250

Coteaz
OM Inq, Terminator Armor, Psycannon, 2 Servo Skulls

5 Terminators
-Psycannon, Halberd
-Hammer
-Halberd
-Sword
-Justicar w. Halberd

5 SBwarriors - Chimera (ML, HF)
5 SBwarriors - Chimera (ML, HF)
Jokaero Weaponsmith, 3 MM-Servitors, 4 Warrior Acolytes– Chimera (ML, HF)
3 Warriors - Psyback
3 Warriors - Psyback

3x Psyflemen

A very resilient Terminator squad fill the same role as the Paladins did in the previous list, but here they are scoring. Coteaz hang out with the Servitors, but near enough to go out and join the Terminators if the Inquisitor runs out of extra wounds :P

Imperial Guard 1250

CCS, 3 Plasma + Chimera

PCS, Flamer
Infantry Squad, Flamer
Infantry Squad, Flamer

2x Veterans, 3 Melta + Chimera

3x Vendetta w. Hvy Bolter

3x Hydra

I'm not sure, every time I try to build a IG list nowadays I just feel that Coteaz lists with Psyflemen are much better.