Reinforcements for the XIIIth Legion: a Land Raider Proteus for the Suzerain Invictarii

With the Iron Warriors able to count on some pretty fearsome artillery, the Ultramarines are going to need to make sure their Elite infantry units - the Cataphractii terminators and Suzerain Invictarii - can close the distance to the Traitors as quickly as possible, or they are likely to get shelled to pieces.  Fortunately, the Suzerain Invictarii can now count upon a Land Raider Proteus to carry them into the heart of the battle.

I am well aware that technically speaking a Proteus is not an assault vehicle, but I didn't want to paint a Mark IIB Land Raider, which looks just like the 40K Mark III Land Raider, so I shall be treating this as an assault vehicle (and paying the cost in points).

It was quite a hefty thing to paint and I probably should have painted it in pieces, but that would have made it difficult to store.  Still, it has come out looking good.  The question is what do I paint next?  I still have a Predator, a Spartan, a Damocles Command Rhino and a Sicaran for the Ultramarines.  Or do I paint the Iron Warriors' Spartan and Termites?  At least they are all assembled and primed to keep me going over the Winter.