Your looking for clean clear sound with sustain for days for soloing??? Sounds like your describing a non-master volume Marshall SL plexi with the volume up over 9,this is why the old school guitar players didn't need fuzz to get sustain.Back then you'd drive the powetr amp section of the am till the transformer overdrove the tubes compressed and the low wattage speakers(greenbacks)got close to distortion causeing a sweet clear sound.
I'm sorry to tell ya ain't no fancy preamp,$3800 head etc... that can duplicate exactly the true sond of a cranked amp,and power sokes don't work either.Youbest bet for live performenace would be to put your stack in the band truck with foam over it,crank it and mic it through the PA and monitors.