AMP against McCormack

I have McCormack TLC 1(pre) and .5 (Power) with THiel 2.2. I am considering other pre and power (under $1500 as used) or Integrated Amp (under $1000 as used).Do you have any suggestions?
I realize this response is the opposite of what you asked but I had exactly the same combination, McCormack TLC, 0.5 Deluxe and Thiels 2.2's and made a dramatic improvement in the system (to my ears, of course) by replacing the Thiels with ProAc speakers.
Have the amp upgraded by SMc Audio. Four different level of upgrades currently available. Go to to find out more.