I am using an Arc 2100 on my ADS 236im's. it is am absolute perfect match!!!
I have also used Alphasonik, Sony and Kenwood. The Sony and the Kenwood were not that great, but the Alphasonik was very nice (a little too powerful for my mids that it was running)
If you can pick up a used Arc amp it is well worth the money, the company keeps good records and the warranty transfers to the new owner. I can't say enough good things about mine.