I am a big fan of ATC and the SCM7s but they are surprisingly power hungry.
I biamp cheapo Behringer amps, a configuration which is supposed to be pretty powerful, especially since I am listening nearfield on my desktop and only use these for my TV and computer.
Other Audiogoners have suggested that the Behringers are not as powerful as their specifications suggest, but they clip suprisingly quickly with SCM7s.
So ATCs can probably take as much money and power as you could throw at them.
"Affordable" might be the hard part - maybe a used Aragon 4004 MK II? Bryston?
I also look forward to other replies.