Thanks for all the responses to my question. I'm going to need an amp that has at least 250watts of power. The Arial 7b is rated at an 86 sensitivity, so they are moderately hard to drive. The used amps that I am considering are...Classe ca301, Classe ca401, Bat vk500 w/bat pack, Pass Labs x250, and the Parasound JC-1. Unfortunately, the McIntosh M501 don't work well with Bat pre-amps, according to a Stereophile article that I read recently. I was drooling over those amps, until I read that. Also, the Bat vk5i has an output impedence of 100k. I've been told that I should try to match the amps input impedence to this, if possible. Thanks for all the help!