SWR and Groove Tubes used to be located in the same building, and Steve W. Rabe and Aspen Pittman collaborated on a lot of products. Some of the early Groove Tubes amps were actually built by SWR (or was it the other way around?). Fender bought both companies, and ruined them both.
Shortly before Fender bought SWR, I bought an SWR Interstellar Overdrive preamp and Power 750 power amp. Fantastic gear, and I wish I wasn't forced to downsize a decade later, and sell it off.
I personally would not hesitate to use a 350x, 550x, or 750x head, the last series that SWR made before the buyout. I also would not hesitate to use any of the earlier SWR pro level gear. I would steer clear of the Workingman's line or the LA series, as well as the Mo'Bass, which as I recall had reliability issues, unless my memory is faulty.
In their day, SWR made some of the best bass gear on the market.