As far as choosing between the Nashbar or other bare frame and fork and a box bike (assuming by that you mean something like a bike from BikesDirect or some other web or mail order merchant), and you view the frames as being more or less equivalent, I'd say it depends on how much wrenching you want to do. It's my understanding that those complete mail-order bikes are pretty well along the road to being assembled already. I think most of them require mounting the bars on the stem, saddle on seat post, installing the pedals and putting on the wheels. Stuff like headsets, bottom brackets, cranksets, derailleurs and brakes are mostly done already. At least that's my impression.