If you're a fan of old school quality amps you have to check out this guys supply. His prices are a bit high but I guess it's hard to argue if you can actually get these amps in new or near new condition. I actually owned the same model U.S. Amp below at one time, amazing amp!! My two favorites below.
http://cgi.ebay.com/US-AMPS-USA-200...9QQihZ020QQcategoryZ18796QQrdZ1QQcmdZViewItem
http://cgi.ebay.com/Ultra-Rare-Prec...2QQihZ020QQcategoryZ18796QQrdZ1QQcmdZViewItem
http://cgi.ebay.com/US-AMPS-USA-200...9QQihZ020QQcategoryZ18796QQrdZ1QQcmdZViewItem
http://cgi.ebay.com/Ultra-Rare-Prec...2QQihZ020QQcategoryZ18796QQrdZ1QQcmdZViewItem