there is yust no way you will better the performance of this amp for $500, imo, unless you go wintage:
30w triode, 60w ul, adjustable tube bias, true dual mono, and gorgeous in either color scheme. use as an integrated, or bypass the inputs and use as an amp.
you can buy direct from china for $500 delivered, or if that makes you nervous, spend a hundred or so more, and make an offer from this canada seller, recommended earlier for the el34 amp:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130300625862
personally, i would yust buy the amp direct from china, cuzz if you have any issues, you are still gonna be better off paying to have it repaired locally than sending it to either place - unless you happen to live in toronto... and even then, it will still be a good deal, imo.