What amp/preamp/integrated to use w/ USHER X-719

I just picked up a pair of Usher X-719s. This was the first part of a rebuilding process for me. The next part would be buying a preamp/amp combo or an integrated amp. I mainly listen to alternative/rock music. I have around $600-$700 to spend (used or new). Any suggestions/experiences would be greatly appreciated. Also, does anybody know anything about the Jungson Ja-88C integrated. It is well within my spending range, but I cannot find anything about in forums or the net. Once again, any input would be appreciated. Thanks, Dan.