Upgrade cartrige Linn Sondek Lp 12 with Valhalla

I love sound of Linn Sondek Lp 12. I have Linn Sondek Lp 12 with Valhalla and Rega 2 arm. I want to upgrade cartridge. Any idea for 200 or less for MM cartridge or should I upgrade arm? I wonder there is any dealer or guru for linn in San Jose area CA. 95148. My current system is Sunfire amp/grand but I only use for phono. I setup biwire amp with NHT 2.9. Sound is increable with bass and midrange.
Any idea for help
You may want to to try this place in San Jose, CA called "Analog Room"

They specialize on analog gears especially Linn LP12 turntables.

Here is their contact info:

Telephone: 408-971-6158

Facsimile: 408-971-7103
Postal address: 1416 Fruitdale Avenue, San Jose CA 95128

They have been tried by fellow-goners in this forums with excellent recomendation. As for me I do my own tweaking as time permitts.

Good luck.