I'm not sure I follow why you need monos for the ML Clarity, but, nevertheless, I think you should check out VTL amps for the Logans. They seem to work very well together.
If I understand though, you eventually plan to keep your 5 channel Acurus amp with the new monos for a 7 channel system. If so, I think you need to make sure the amps have similar gain and sound characteristics because it looks like your center channel will be driven by a different amplifier then the front-channels. I'm not a home theatre expert, but you may want to discuss this issue with a dealer who is.
If I understand though, you eventually plan to keep your 5 channel Acurus amp with the new monos for a 7 channel system. If so, I think you need to make sure the amps have similar gain and sound characteristics because it looks like your center channel will be driven by a different amplifier then the front-channels. I'm not a home theatre expert, but you may want to discuss this issue with a dealer who is.