I have had good luck with La Minta estate's Costa Rican Tarrazu (sp?). It may or may not be overhyped, but I like it. The other bean I'm currently roasting is the Kenya AA Mika auction lot from sweetmarias. (La Minta is also from sweetmarias). I tried some Sumatra something or other (NOT from sweetmarias) that never turned out well for me, but that was probably because I didn't know what I was doing and didn't have a thermometer. For some reason my roasts always turn out darker than they are "supposed" to turn out, so if I go only by color I get an under-roasted bean.
So as you can see, I'm far from a coffee great, but I think javafool said he had 70 lbs of green beans on hand! Let's hope he weighs in on this. I would say that a good option might be to order a sampler of some kind or other and roast a bit of many different beans. Then order 2 or 5 lbs of your favorites. Can't go wrong with any sweetmarias offering, I'd say. At first, controlling the roast is going to be a bigger factor than what bean you choose.
By the way, I could lend you a book on home roasting if you promise to send it back in a month or so. PM me if you'd like to borrow it.