For the price range you state, either of the Nashbar CX bikes seems ideal, with a change of tires. Bikesdirect has some CX bikes too that may fit the bill.

A vintage sport type bike would also work well frame-wise. Just remember, unless it has been updated, you'll have downtube shifters (or stem). They'll work fine, and some people like them, but I much prefer brifters myself.

As others have said, 28 or 32 mm tires will probably be ideal for your purpose. Good luck!