Curiousgeorge,
A Hafler Transnova 9300 does very well with the Heresys and sells used for less than $400.The 9500 or 9505 will drive almost anything(probably overkill for the Heresys)and should set you back between $600 or $700.My favorite SS amp is the Muse model 160 and would cost about the same as a 9500(6-700 dollars).An Aragon 8008 or 8008BB(also overkill) would be less than $1000.You may be able to pick up a Plinius SA 100 mk.3 for around $1500.
