OK, I've spent the last 3 days reading as much as I can in these forums, checking out some of the LBS, and generally trying to get my head around what I want in a single speed. To narrow it down a little, I've decided I want to spend less than $400 (ruling out the IRO), and I need brakes. I'd prefer bullhorn/upright bars, and I'd prefer the ability to flip flop the rear wheel as I get more comfortable riding single. Based on these needs and wants, I've narrowed it down to the following options, but I still have some questions:

Redline 925 (there's one on ebay right now for $350ish).
Windsor Clockwork (BikesDirect).
Dawes SST (BikesDirect).
Motobecane Messenger (BikesDirect).

Seems like the last 3 are roughly the same quality. In fact, it seems like the Clockwork and the SST are the same bike, except the SSThas bullhorns. Is that true?

From reading the posts, it seems like the Windsor the Hour is highly recommended, but there aren't a lot of comments on the Clockwork - what are the major differences/pros/cons?

Thanks in advance.