I am planning to build my first fixed gear bike over winter break. I have a 22" 1983 Lotus bike with horizontal dropouts and 27" wheels. I am gonna order either the Suzue or the Nashbar flip flop hub in a couple of days.

First of all, how should I determine what size cog to use? I don't think there is one gear ratio that I could really use comfortably on all the streets I ride on around here. Should I err on the side of uphill and expect to use the brakes more than usual on downhills?

Also, most of the fixed gear bikes I see have curving up handlebars which I think look pretty cool. Can I make them by cutting off a drop bar, of which I have a couple lying around. What kind of brake levers work with them?