Thanks for the suggestions guys. The Presonus looks pretty good, I'd be a little nervous about the reports of too-hot inputs, to the point of being unusable. I guess you (hellbastard) have not had that issue?
The Tascam also looks good, there are a few models with different input/output configurations in that price range that all seem pretty good, actually.
After doing some more research I think I want to be sure I'm getting the best quality signal into the computer. In particular, I want to be sure that the full dynamic range of my playing is translated well onto the tracks I'm laying down. So I think that means having a unit with decent mic pre-amps, a high bit and sample rate (higher than 16k/44.1 if possible) and a USB 2.0 versus a 1.1 port, and possibly having an external power supply versus bus-supplied power. It's difficult to find all of these things in one unit, however, at least in my price range. Also, I may be off base in thinking all these things are requirements for what I
think my needs are at this point.
Another issue that makes me hesitate on a purchase is that pretty much every model in this basic $100 to 250 price range has a not insignificant number of bad reviews. And although a big chunk of that is probably user error, it's likely that I would be one of those guys who can't figure out how to get the hardware to work with the software and would be posting bad reviews.

It's also the fact that not every interface works with all computer configurations.
I'm just trying to avoid that scenario, and be as certain as I can that all the pieces play well together.