GURPS Unreal

I am developing it. There is going to be a big RPG event in my city (big like, it is gonna occupy a whole campus of a big university for a few days). I signed up to be a GM, and I decided I’d make the environment set on the world of Na Pali from Unreal. The plot revolves around rescuing classified material from the ships that fell into the planet (Rikers, Krann, Prometheus…).

I have everything planned but one… the part that deals with numbers. I am reading Cyberpunk & Ultratech II to come up with statistics for the weapons but I don’t have any ideas. I think I’ll just end up copying the weapons of GURPS Doom and renaming them if nobody helps me >_< but what really bugs me is that I am just starting to come up with the characteristics for the monsters. I’m using Compendium I and Fantasy Folk (I don’t have Space, but I feel I won’t need it) to come up with them. The Nali are easy enough… But I think the skaarjs are going to be a pain to design so I will aprreciate any help that can be given on them.