I had a MT system preamp with a few modules many years ago when they were still in production or just after they stopped making them.
IIRC, I think I sold them to fund a new Axe-FX Ultra..
After selling my Engl E530 tube preamp and deciding to keep my Engl E850/100 power amp and cabs, I've thought about getting a Syn2 rack preamp, and a couple /few modules. Vail, SLO II, Pittbull.
The power amp is 6L6GC, and I have Marshall / Marshall -flavored Engl and Bogner amps, so I'd focus more on preamp modules that come from 6L6 amps, and I have Fender and JP-2C 6L6 amps....and a Diezel VHX with KT77.