get some sugino 75s. i just got my set in the mail, complete with a 49t sugino chainring for $175. really good deal since the chainrings alone are around $45 and the cranks w/o ring sell for $175 through lots of retailers. they're not the cheapest cranks, but not the most expensive either. but they'll last you from frame to frame. put an 18t cog on the back and you'll have a nice gear ratio for flat and hilly terrain as well as 18 skid spots.