Minimun amp rating of and esc for 2s & CMS7700

I'm not sure, but I do know the 7700 is a hog. The MM esc will get quite warm while pushing any 1/10th off-road with the 7700 motor. 1/10th on-road might be ok. I'd guess you'll be in just under the 100A range pretty easily if it's in a decent sized vehicle, but that's a wild guess.

Like mriccucci said, it depends a lot on the application and load on the motor. Perhaps if someone is running a similar setup as you will be running and is using the same running gear you can get some input from them. We'll need to know what your plans are though.

J.