Draigo and a squad of 6 paladins. They will have two psicannons, the apothecary and the brotherhood banner (ensures force activation which could be difficult against Nids otherwise. There is also a 10 man strike squad with a psicannon and demon hammer.
Heavy support - 2 dread knights both with psicannons and incinerators, one will have a demon hammer.
aegis defence line with quad gun
Necron Allies
Illuminor Szera, a 10 man immortal squad with tesla carbines and a night scythe.
I realise its only 28 models but they all put out a serious amount of fire power and with most of the grey knight melee weapons being ap3 I'm hoping to be able to kill lots. My main worry is the fact that the dread knights won't be able to touch any of his flying monstrous creatures if he keeps them airborne but that is where I'm hoping the quad gun and night scythe will come in. And yes my inner fluff fiend has died a little after writing this list