How big is your listening room? I agree with you, the Perreaux Radiance R200i is a great piece. I've had mine for a bit more than a year and I'm extremely happy with it, and I don't plan on letting it go for a long time. Just for reference, my system also includes a Simaudio Moon Nova LE CD Player and Polk Audio LSi15 speakers(a REAL steal at $1500). Anyway if I were looking to upgrade(and of course this is just me) I'd probably look at my speakers first. I'd like to try a pair of Amphion Xenon or Gershman Acoustics Avant Garde RX20 speakers. If I had the funds, I'd check the Paradigm Signature S8 speakers out. Right now the next upgrade for me will probably be power conditioning. I'd like to establish a dedicated line, and maybe later down the road get a Shunyata Research Hydra 8. Anyway I could understand you having a tough time letting the Perreaux go.
By the way, unless your listening room is of really huge proportions, I don't think you'll be running out of power with the Perreaux's 200wpc. So if you're about to try different amps, I think it would be mostly about looking for a different sound, more than just about raw power.
Having said all that, the Parasound amps are very very impressive. I'd owe them if I could, and if I had speakers to make them justice. They perform like REALLY REALLY expensive amps(not that they are cheap, but you get my point). Not much more I can add to that...But again, if you're going to have those amps, you probably want speakers that can make them some justice...The Paradigms Studio 100 are really good, but something like the S8s would be more revealing. For my tastes think something like Dynaudio C2s would make an awesome pairing with those amps(but of course I can't afford either...). :-) Anyway, good luck with your search, it definitely is a fun ride checking out good audio gear.