Was wondering if there was any information on what the frequency response is for the 2200 above 20kHz? Say, up to 45kHz or 50kHz? TIA.

I don't think anyone over 18 can hear much at all above 18khz, and I don't think any digital sources have any information in that area.... vinly might, I'm not sure.

I'm thinking SACD or DVD-Audio, or possibly the next-gen HD audio content. I hope that I might get some speakers that hit 45kHz later this year.

The amps on AV123 have specs for that range, but didn't see anything here.

Many amps don't have anything listed in that range, because aside from a handful of super tweeters there are no speakers that work in that range and there are no human ears that can hear it. You might give Outlaw a call and see if they have anything.