Spend my $1000 on a turntable

Why do you want to sell Direct Drive turntable to buy more expensive Belt Drive turntable?

I understand an upgrade from one Direct Drive to another Direct Drive, but to a belt drive .... ???

All you need is to replace the stock tonearm on your Technics SL1210 mkII if you want to upgrade the sound. The cheapest new option is Jelco, the armboard for Technics available on ebay. It can be a decent vintage tonearm too, something like the Luxman TA-1 if you gonna use high compliance MM cartridges. If you don’t want to upgrade tonearm you can, indeed, buy a KAB fluid damper and re-wire the arm with Cardas or Discovery wires internally. Then find Zu Audio Mission Phono cable on ebay, cut and solder it directly. If you want a silver wire then you can buy Signal Cable Silver Resolution. I use both cables with my gear.

You can also buy brand new Technics SL1200 GR for about $1700 and it does not require upgrade, except for the mat. Saec SS-300 mat is reasonable priced, Micro Seiki CU-180 copper mat is more expensive.  

If you’re a user of Direct Drive then moving to a Belt Drive is not good.

Technics metal plate can be painted in any color, they are also for sale separately.

You need a much better cartridge for any turntables, those cheap belt drives does not come with a good cartridge. Cartridge is the most important! Ortofon M20FL Super with FineLine nude diamond is superb vintage MM for very reasonable price (under $300).

+1 bpoletti & grinnell! A VPI HW19 painted gloss red with a good arm (Jelco) and cartridge (Grado) would be "da bomb"! Maybe I should paint my HW19 red too!

This Rega Planar 3 in red for $750! Then get the Ortofon 2m Blue. There is nothing wrong with them except for literally a scratched box. I bought the same one very recently. Cheers!

https://www.musicdirect.com/turntables/Rega-Planar-3-Turntable-Red-No-Cartridge-DAMAGED-BOX

There is nothing wrong with them except ... 

.. that they are cheap belt drive turntables and can not compete with decent Direct Drives in terms of speed stability. These Regas looks like a toy and act like a toy, a mediocre turntable for those who's trying to save on everything. These turntables must be avoided like any cheap modern belt drives, especially when brand new SL1200GR is just $1700 (and that plastic Rega toy is $750). 

As a drive Technics SL1210mkII is superb and the OP already have it, just add new arm with decent cartridge. Technics can be upgraded anytime, the Rega can not be upgraded, it's a junk, sorry. 

My opinion....

I tend to agree with @chakster in that it would seem a good idea to repair the SL1200 (and maybe the phono stage) and mount a good cart. Maybe a Jelco SA-750 of a new Jelco 850 arm could be a significant upgrade, everything else being equal.

I also agree with his assessment of (IMO, all) Rega tables, but disagree with chak’s generalization related to belt drive tables. Off-center holes and the process from mastering to final pressing is the cause of pitch instability. Actual speed stability is fine in just about every non-toy modern turntable. (As I have opined in other threads,) What seems more important is drive voltage in AC synchronous motors. Dropping the voltage (such as using a cheap Variostat) significantly reduces any noise making its way down the drive belt(s) from the jerky A/C drive motors. This method just won’t fix the problems with Rega tables, though.

Just my opinion. YMMV, YRMV.