[Balanor]

...Gilgeam who hasn't been put in game yet...

This is incorrect. Gilgeam is available for deity selection in-game. However, are speaking of no in-game temple for him? If so, that is correct. But I would encourage your PC to start one via the tools available (player housing, tailor models for faction items/cloaks, recruiting other NPCs and PCs, posting on the in-game message boards, etc) and let the DMs know too that your PC is trying to start up a new temple.

If the temple grows big/important enough it could eventually warrnt some design time for more permanant temple quarters, faction contacts, and so on.