I didn't like tubescreamers for clean boost, e.g. putting it after your main dirt. The mids are too pronounced, even with a bass boost mod and various clippers (or none). Sort of like a lo-fi effect going on.
Why don't you take the opportunity to build your own? Clean boosts are among the simplest you could ever build. As for me, I like those that have transparent qualities, or even those that add a touch of treble, then roll down the tone knob and adjust on the fly. Let the tone capacitor do the mids your looking for, I guess.