Bona nit!!!
I suppose that you know it, but you can also use Traveller: The New Era rulebook. Same Twilight:2000 / Dark Conspiracy set of rules and good suggestions about futuristic weapons, starships etc. And with interesting supplements, if you like the "hard" science fiction.
Ah! And this weekend I've played D&D d20. The d20 system seemed to me totally antinatural! Powers, feats, levels, AC, Hit points...
Uf!! I've made my choice as GM. T2K/Traveller:TNE/Dark Conspiracy for modern/military/sci-fi environment and GURPS 3ed. for ancient/medieval/fantasy environment.
I'm taking a look to the Project Phoenix. Seems interesting. I know for sure that one of my rpg groups woyld enjoy this kind of setting.