Differences between MM or MC/Recommendations?


I really enjoy vinyl. I have two questions: What is the difference, sonically, between MM and MC cartridges? And, what recommendations can you make for a $1,000 and under retail priced cartridge?
My system: Rega Planar 25, RB600 arm, Rega Super Elys MM cartridge; Phonomena Phono Preamp (which is just about infinetately adjustable for MM and MC, also to be upgraded soon) Musical Fidelity NuVista M3 Integrated Amp; Sonus Faber Grand Piano (not the Home version); CAL Audio CL-20 DVD/CD player; Harmonic Tech interconnects; MIT T2 Biwire cables. I plan to keep everything except the cartridge and the Phonomema Preamp. Thanks in advance.
smwdrtwin
This guy Juki from HK has good deals on Ortfon MC's and other carts.His shipping might take some time but a freind got an SME arm and liked the price/service.Hey how do you like that Music Fidelity M3?What else was in the running when you got it?
Fletchi- Another thing that TWL said that makes alot of practical sense is "the execution of design and the system compatibility may be more important than specs or theory".
The numbers that a marketing department puts on a literature sheet doesn't make a sound!

Regards
Jim
To mention 2juki I've acquired from him Lyra Helikon for $1200 brand spanking new. I figured out that I really do not need Immedia's warranties on that since they're all don't make any sence becides I've got it at arround 45% discount.