I'd go with the JMW 10 or 10.5 but with the caveat that they don't handle edge warps with much grace, at least with the Grados (I have a Reference too, the original version).Then I'd ditch the clamp in favor of a Ringmat. This ridiculous-looking thing (which isn't supposed to work well with VPI TTs) really did wonders for my early model TNT. At least see if you can borrow one and try it.
The Walker unit undoubtedly bests the earlier model VPI motor controllers, but I would question whether it beats the SDS, which is the best favor I ever did for my TNT.
The Walker unit undoubtedly bests the earlier model VPI motor controllers, but I would question whether it beats the SDS, which is the best favor I ever did for my TNT.