You can use an MC50 MC250 MC2505 MC100 MC 2100 MC2101 up to the MC2300. All seem to have the circuitry we are after tone wise. Those are listed from smallest amps to largest, i may be skipping one or two. I can play a pretty good sized gig with my MC100 (a mono 100 watt amp). A MC250 is very common and affordable allowing you to have either 2x70 watt amps or bridged at around 140 watts or run two speakers in stereo @ 70 watts each. That is more than plenty for most folks.