i'm using a bendix 6106 rectifier, electro-harmonix 6SN7, and sovtek KT66. check this thread here for more tube options:
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1112733965&read&keyw&supratek+tube&&st0
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1112733965&read&keyw&supratek+tube&&st0