you need a brake with a plain old nut in the back, rather than a recessed bolt, as is common on more modern road bikes. you can get a brake like this for cheap at the times up(!) open shop night on thursdays. they also have plenty of old road levers.
if you want a prefer a cross lever, I can sell you one, and show it to you first (I live in NYC too).
Thanks for the help so far guys, I'll probably be heading down to times up on thursday to see if I can get this hooked up.
Another thing... strange noises seem to be coming from the headset when I turn the bars. Can I just order any old generic 1" threaded headset (say, from nashbar) and expect it to work / fix the problem? I'm guessing times up has a headset press?