Yeah, there's never a good time to ask about lightguns. I'm still trying to figure out the AimTrak and Andy is doing what he can on the software/firmware side of things. Right now, the AimTrak hasn't been tested by the public enough to be recommended, plus it's still evolving. The TopGun has its problems, as does the Act Labs gun. The Wiimote, to my knowledge, isn't much of an option.
I say wait and see what the general concensus is on the AimTrak.