Space Marine help

[Charon]

For a pen & paper game I'm thinking of playing a Space Marine, the system is GURPS so it probably won't be too hard to translate. But for the most part I'm rather unsure of what all Space Marines can do and the quirks of the different chapters. I know that they are very strong and fast, and don't need to sleep, but what else is there? Any sites you could point me towards or just outright info (if you have the time) would be appreciated.

[The Silence and I]

Whee!
Mostly history, process of becomming a SM, whatever. I yawned.

Wheee!
More game-stats like stuff, it tells you what the 19 implants actually do.

[SirNitram]

Chapter quirks vary wildly, from the psychopathic Blood Angel Successors, to the Cursed Founding(One Chapter had the nasty tendency to burst into flames when entering combat), to all sorts of things. If you can think of quirks within the general gist, we can probably find a Chapter, or make one.

Hell, for the 40k RP, I bashed together a Chapter on my own. High-tech, non-hit-and-run, all on their own buggers. I keep thinking that they wind up a bit like Loyalist Iron Warriors, only without the artillery peices.