Which cartridge for planar 3/rb-600 arm?

Hi all,
Just trying to collect some ideas on a new cartridge. I have been using a Grado gold with nice results, but I am bitten by the upgrade bug. My budget is $500.00 give or take. My pre can do both MM and MC so they are both in play
I have been thinking along the lines of the Sumiko BPS EVO 3, Grado platinum, shelter 201, etc
Any ideas or suggestions would be greatly appreciated.
Thanks as always
Consider a Denon 103 or 103R.
I'd look for a used Shelter 501 MKII, or a Zu or Soundsmith modified Denon 103r.
what Mmike84 said
The Rega Exact 2 sounds absolutely wonderful on my Rega P3-24/RB-301 set-up. There's a lot going for the natural synergy between a Rega cartridge, Rega arm, and Rega table. They all seem to work beautifully together. Good Luck, and Happy Listening !!
Agree with Adam 18 on the Rega Exact. The best part is that cart alignment is a no brainer coz the Rega Exact has 3 fixed holes for the head shell screws. If cart alignment is not a 'consideration' the Denon 103 R should get the nod IMHO.
Best of luck.
Thanks all
I went with the Denon DL103 and am very happy with it so far