CC, good advice from 4everfrio. We camp a lot in our National and State Parks and Forests and, as far as I know, the 'no popups' rule applies only to some of our western lands where grizzlies might be encountered.
Not too many of our National Parks have sites with electrical hookups so, if that's where you expect to camp and if AC is a must, you're going to need at least a 2KW generator - a 3KW unit will be required for older or larger AC's. Expect to spend somewhere between a thousand and sixteen fifty for a quiet Honda or Yamaha.
You might also want to visit the popup forum at
www.rv.net - Lots of experience on that site.
Good luck in your search - Al