What you need is a "sport touring bike". For a light tour, you need to mount a rear rack and panniers, I suppose. Plenty of bikes have those.

Bikes Direct offers the Fantom CX cyclocross bike with a triple for $579.

http://www.bikesdirect.com/products/..._cross_cx3.htm

That looks like it should fit the bill for you, and they offer it in up to a 64cm size.

Here are their pics of the bike set up like I imagine you would

http://www.bikesdirect.com/products/...3_racknfender/

Since you say you would tour with a light load, you should be able to get by with a rear rack and panniers. Maybe a handlebar bag too?