Suggestions for arm to replace VPI 12.7


I am thinking about replacing the 12.7 tonearm om my VPI Classic 3 turntable. My budget will be about $4000, and I'm willing to buy used. Does anyone who has replaced a VPI 10" or 12" tonearm have any advice regarding a compatible replacement?
sdcampbell
I have no knowledge, other than preferring that new 3D arm, compared to their regular arm, done on Michael Fremer's site.
The new 3D tonearm is terrific. I upgraded to the 3D arm on my Super Scoutmaster Reference rim-drive and it is a substantial improvement over the 10.5i arm IMO.
I'd love to know how the 3d is compared to a Graham (I know-read the review but tough to get an honest vpi review with the dollars they spend advertising-even MF didn't knock the MDF $30k DD TT)). Does anyone know if you can easilly replace a 10.0 with a new 3d w/o redoing armboards? I would do that in a heart beat. I have a hopped up VPI tnt jr with 10.0 jmw.