Ok - problem solved. I should have done this in the first place. I got home and measured my other bike ... the 57 cm should fit me pretty well. Thanks for all the input.

Could anyone suggest a wheelset, or a place to go to figure out what I would like. I've pretty much settled on Campy (Centaur most likely) for the rest of the build, but am pretty clueless re: wheels. The bike will see 150 - 200 miles / week, some group rides and hopefully a 200k brevet, but no racing. I'm 5'11 and 170.

Thanks!!