The drag isn't that big of a deal with a frogging reel. You're gonna want to tighten that sucker down all the way so it doesn't slip an inch.
I used a $50 Daiwa Strikeforce 100SH 7:1 reel all year last year and had a blast. It's actually a surprising decent reel for the money, and it takes up 31" of line with each turn of the handle. I would recommend putting Reel Grips on the handles, though. They are hard plastic so they get a little slick.
Really, all you're mostly doing is twitching the frog with the rod and taking up slack line with the reel. Frogs are heavy and easy to cast with a cheaper reel, too. This is THE one technique where a premium reel is not going to help you very much at all. I feel the rod is way more important than the reel when frog fishing. If the setup is for strictly frogging, save a few bucks on the reel, you'll end up dropping it on a nice rod or on frogs anyway.
One the other hand, if the setup is not just for frogging, but also may be used for flipping, pitching, jigging, then disregard the earlier statement and go with a Curado or Revo.
http://www.fieldandstream.com/articles/gear/fishing/2009/06/daiwa-strikeforce-100sh-baitcasting-reel
http://www.reelgrip.com/products-page/