Another great, cheap speaker is the Polk R15. List price is $180 but they're pretty commmonly available online at $60-75 and I've seen them on sale at Fry's for $50. I had a pair for awhile and did try them with the t-amp. They're reasonably efficent at 89dB and sound a lot better than you'd expect at the price. Here's the Amazon listing with a lot of user reviews.