I would not under-estimate how good the Quad II amps are with the 57, though they are very underpowered for most applications, my Quads sing with them. When I originally had the 57s set up in the '70s, I used an ARC Dual 75a (which was new at the time) but I think the panels sound even better with the little Quad amps, which are readily findable and easily repairable. The Bedini 25/25 is supposed to be great, but how easy is it to find/condition/repair?
I did splurge on the tubes, and found NIB GEC KT 66 matched quad for the amps, use a NOS Mullard rectifier and a GEC (rather than Walker's preferred Mullard) EF 86. (Those were also true NOS, originally designed with bare wires to be soldered into a circuit, Tubemonger converted them to use tube pins and fit into a conventional socket). Keith Snook's page is pretty good on the amp.
I did splurge on the tubes, and found NIB GEC KT 66 matched quad for the amps, use a NOS Mullard rectifier and a GEC (rather than Walker's preferred Mullard) EF 86. (Those were also true NOS, originally designed with bare wires to be soldered into a circuit, Tubemonger converted them to use tube pins and fit into a conventional socket). Keith Snook's page is pretty good on the amp.