What cart should I go for

I"m not using anything in that range, but I've been hearing very good things about the Hanna. Otherwise, I now use a Dynavector XV-1s, but once had a 20x2 that was very nice.

Hana SL mc for $750! Best under-$1K cartridge today!

There is a used Hana over on audiocircle.

Fidelity-Research PMC-3 is superb for your "12 inch Jelco if you want something very special with Air-Core Coil, Vital Contact Line Diamond, low compliance MC designed (influenced by FR-7f thinking) by legendary Ikeda-San. 

If you'd like to try MM then definitely Victor X-1II  (Beryllium/Shibata). 

The Hana is a pretty fine cart but it is very light. If you go that way you may need to add some mass...

There are sellers on EBay with weight that mounts on top of the headshell for about $5.

I had audioquest PT -9 tonearm same as Jelco 750 matched with Soundsmith Zephr that sounded really good together. Don't know how heavy your counterweight is but with pt9 and zephyr the weight was having to ride to far back on end stub for my liking. So I added a Expressimo counter weight that also improved the sound

Dear @sonicstoog : A little over your budget but if you can to strech it you can't go wrong with either of these alternative. Worth rewards for your listening times:

https://www.audiogon.com/listings/lis9ch23-sumiko-pearwood-celebration-ii-rebuilt-from-soundsmith-ca...

https://www.audiogon.com/listings/lis9cfic-dynavector-xx2-mkii_under-50-hours-used-for-setting-up-tu...

https://www.audiogon.com/listings/lis9ca13-lyra-skala-cartridges


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.