I just installed the RS Labs RS3 rotating headshell on my Dynavector arm. Results are very promising. the headshell is not hard to use like the arm and comes with a usable arm lift.
The sound is very airy and "natural" with excellent ebb and flow. Lots of spatial information and life. If you have an arm with a interchangeable headshell, this might be your ticket.
As for the arm, I have not seen one for the low $500 price used but sometimes you'll never know.