Got the table now I need a good arm and cart combo

The rega RB300 is a match for the townshend. In fact, their excalibur tonearm is based on an RB300 with different bearings and other stuff depending on the version. The Rock III will take a high energy cartidge, especially when using the trough. Do you still have the cartridge paddle attachment. I am using a Monster Alpha 2 on my Rock III with great results. Try the ZYX Airy series made by the same inventor. Does your seismic sink still hold air?

Holds air, has trough, but not sure about the cartidge attachment? Where can you get one of those?

you should be able to get one from townshend itself. They still use the same setup on the newer tables, just a double version.

I do have the head shell for the trough. Was thinking it was something different. Why are you moving the hadcock arm?

Years ago I ran a Rock for a while. I removed the trough and ran an Eminent Technology air bearing arm with a Shure V15 Type 5 - actually sounded pretty good. ET's can be had quite cheap if you look.