you have a 1" quill stem currently? you'd save some money not converting to threadless IMO, and there are pretty good 1" options. i have the very evil 1 1/8" quill stem on the kona fire mountain and there is almost nothing made like that anymore, so i'm considering a new fork and all sorts of expensive crap...

anyway, that's one thing. that bike have eyelets, braze ons, whatever for rack and fenders? if not, a good rack will probably cost you a little more than it should; but you could always get a seat post rack. axiom makes a pretty good one.

wheels are where you will/should spend $$, but it doesn't have to get ridiculous. how old is that frame and what size wheels was it built for?