Amp rec's for newly acquired Monitor Audio GR60's


Hi all,

Just getting back into 2 channel music & recently acquired a pair of Monitor Audio GR60's (For $250 !) in great shape except for a semi-fixed dent on one tweeter (can't really hear it, but may swap it out anyway at some point). Now I'm on the hunt for a good used amp to run them. I'm currently using a Pioneer Elite VSX-52TX. However, the 2nd zone (& bi-amping) speaker posts got bent in a move & no longer work. I'd like to bi-amp these (they can be tri-amped).

I have seen several older amps in my area being sold for semi-reasonable prices, but not sure if they are to old to still sound great.

some of the ones I see are:
PROCEED FROM MARK LEVINSON AMP2 - $650 (a bit expensive for me right now)
Vintage DBX BX-3 Amplifier & CX-3 Preamplifier - $650
Sonographe SC-1 / Sonographe SA-120 - $625 (said he would sell the SA-120 for $300)
Adcom GFA-555 350w at 4ohm 2 channel power amp = $450
Adcom GTP-500 Tuner Preamp and Adcom GFA-535 Amplifier - $300
VSP Labs trans mos gold edition 2 channel power amp 300+ watt @ 4ohm = $400
Nikko Alpha 450 Vintage Amplifier - $250
Yamaha m-45 natural sound 2 channel power amp with bi amp abilities recently recapped - no price

I'm kind of only looking for an amp & not a older pre-amp as I need a DAC in my pre-amp & thinking of just using my Pioneer Elite as one. One problem I may have with this setup is how to bi-amp the speakers using the pre-outs of the Pioneer in Stereo/Direct mode (which supposedly does not use all the other unneeded circuitry of the surround/video processor).

Any help/advise is appreciated. Thanks.
ring30