Well if you can get past the rampant proximity effect in MOST non-big name profiles, then I'd say AFTER thoroughly going throughout he ones that chi with the Kemper, start at the Rig Exchange. There is a LOT of crap there but also some really good stuff.
I highly recommend V/Rad Studios (My fav JCM800 profiles), xRay Profiles, TopJimi (dude has some great Marshall stuff). You will hear a lot around The Amp Factory and MBritt. Both have good profiles but like anything, profiles are hit or miss.
You will weed through 500 to keep 20. I posted a Mercyful Fate clip I did this morning, and put a link in there to where a guy on the Kemper forum named Tim Owens has done about 150 Friedman Brown eye profiles, many are GREAT. He is working on the Friedman Dirty Shirley and Small Box as well as Splawn Quick Rod.
The Kemper users I have dealt with, mostly the whole online community, have all been REALLY cool and supportive.
Welcome to the fold brother. Best piece of gear I have bought in years.