Since you've already got a PODxt, why don't you look for a keyboard amp? You can probably find a used Peavey keyboard amp for a decent price, and will get grate results like this. This setup sounds really good, because the keyboard amp is designed to give a flat response. They can usually get pretty loud too. It's almost like running your POD through a mini PA. I'd sugget taking your PODxt along with you when looking for an amp, and see how it sounds. Try different "what are you connecting to" settings to see what works best.

Or, you could get a >Crate PowerBlock< and a cabinet like >this one<. I've heard some soundclips of the PowerBlock, and was extremely impresse with it! It sounded like it would be just right for what you'll be playing. You could also use it as a dedicated power amp for your PODxt.