I apologize if this has been covered before -- a search did not provide me with adequate answers.

I've read Sheldon's article and I'm convinced I'd both enjoy and benefit from riding fixed gear. I have a $400 budget, which could buy me a Kilo TT. But, I have a 1983 Trek 400 which I could convert, allowing me to spend the money on better components while saving up for a better frame. Which would you recommend?

My next question is, if converting is best, on which parts should I spend my budget? I know I'd at least be buying an entire new rear wheel and a chainring (the Trek currently has a 52t and 42t, and I'd like a 46 or 48), and I'm thinking I should spend the rest on a crankset, a BB and a front wheel (so, buy a wheelset). I do not want to skimp on quality (anymore than is necessary with a $400 budget), and I'd like a balance of durability and low-weight in a wheelset. Currently, I'm looking at the Sugino RD2, its companion BB, and Mavic cxp 22's w/ formula hubs.

FWIW, I'll be commuting about 100 miles a week on the bike in an urban area (I deliver for Jimmy Johns and bike to class, publix, etc).

Any and all advice is welcome.

Thanks