Scott--If it's not too much to ask, when you have time would you be willing to share your favorite amp/IR pairings?
Name the amp, I'll name the IR's. Just depends.
Scott, do you have a good way to audition the Redwirez stuff? I've been thinking about trying them but with the limited number of user slots it doesn't seem worth the money to me. Are you doing the IRs in your DAW or in the axe?
MixIR is a huge tool for this sort of thing.
Red Wire Impulse Responses | mixIR2 High Performance, Zero Latency Convolution Plug-in
Own Hammer has their own too:
Axe-O-Matic DSP - $20.00 : OwnHammer.com - Store
And a third party to rule all the Red Wire and Own Hammer:
iProductions Audio
If you don't want to spend money or use a DAW, it's easy (and free) to also just drop different IR's in the User Cab slots and use a stereo cab block to listen. Takes some more time, but no money.