Space has military templates that I use quite a bit, plus advise on building aliens, and a terrifying star system generator. You have to be crazy to use it though since there's no software for it. Biotech has lots of interesting racial tempates that can work for aliens. Ultratech has all the weapons and gear you need, must of the game seems TL11. Light armor would be TL11 fabric suit, forget what its called, Med TL10 hardsuit, and heavy TL11 hardsuit, or space combat armor since that's vacsealed. There's no gravtech shotgun, but the rest of the weapons are there. Haven't read the psionics book though, but the basic set should be good enough for mass effect. Biotech also has better cybernetics then Ultratech, my opinion though. None of the other books I have would be useful though, thier mostly just fluff. But Biotech and Space have tons of character and racial templates, Ultratech has the gear.