Rich,
OK, sounds like amplification is sorted for you. That's good - more money for everything else.
Have you found out exactly which x-fi soundcard you have yet ?
Also, do you have a reasonable microphone yet ? Or is that going to have to be included in the budget too ? Can't go wrong with an SM-57 IMHO.
BTW, I'd still thoroughly recommend chatting to the DV boys. They will be switched on to the whole market. Individuals, like me, tend to be rather blinkered and focus only on the particular type of equipment that we tend to use. There's just so much out there.
Alan