The only difference between the '07s and the '08s are the cam colors and which camo comes as the standard offering; MO Obsession is still available, so conceivably if you ordered your '08 in Obsession the absolute only difference would be the switch from silver cams to black cams.

BowTech does not sell direct to consumers, so your best bet wouldbe to go through your nearest authorized BowTech dealer.

There's really no way to "tune" anything to do with cam lean; I've owned three Guardians in the last two years, and it's never been an issue on any of mine whatsoever. We just had a pretty good discussion in the tech forum on tuning binaries a week or so ago on a thread started by HCA PA or something like that (forgive me for forgetting the actual initials before the PA aprt...)