my suggestion, find a $5 old steel frame with horizontal drops, make a SS out of a rear wheel, one of the two ways (depends on the hub, see sheldon as you've found)... see how you like it

oh, and my favorite site to buy frames and bikes is eBay

as for brands... IRO is good, Surly has some good stuff, Bianchi makes the San Jose which is pretty cool. many many companies make SS's now