Best Cartridge

I have a Thorens TD 166 MKII with a Magnepan Unitrac 1 tonearm.

I need to buy a new cartridge for it. Any suggestions that won't break the bank?

I suggest you post your question on Analog section and you will get a lot more response.
Shure V15mk5 MR! A world-class mm cartridge that works best with a low-mass arm! I own one (and will not part with it!). My tonearm of choice is the Grace 707.
Is there a way to move it or do I start another discussion. That seems redundant.
No way to move the thread that I'm aware of, but you can check the user help topics to be sure.  The analog section will get you more input as imhififan notes.

Regardless, I suggest you consider what you're using for speakers and pick a cartridge accordingly.  Personally, I prefer a tight, defined and uncolored sound.  For me with my old-school British monitors, that meant Dynavector and Ortofon in my Unitrac back in the day.  DV is MC only, but Ortofon offers a lot of really good MM.  You could try a 2M Blue or Bronze or Black MM depending on your speakers and budget; they are very well-regarded.

Do be careful with your arm:  The 44 gauge Litz wire isn't available anymore so if you develop fault, it will be virtually impossible to repair.  Go ahead and use it, but save your money for an eventual replacement.  VTA on-the-fly arms are fairly rare and tend to be costly, too.  You'll have to be patient for a used unit to come on the market. 

Good luck & happy listening!