Need advice for upgrading my analog setup

A great choice with the SOTA. I have a Star Sapphire with vacuum hold down, an SMEV arm and a Kiseki Blue cart and it’s magic to my ears. Once the SOTA is setup it’s pretty much play it and forget it. Great isolation and speed stability and the table just rocks! I also have a nice VPI setup but I like the SOTA more overall. Just make sure your phono stage and cartridge are up to the challenge or your overal happiness with the table might suffer a bit. It’s worth the best you can afford to throw at it.

As others have mentioned I'd strongly consider upgrading your phone stage as well. You can get a new Musical Surroundings Nova III for 1500, used even less. Dead quiet and linear. Great piece. There are others in that price range that will be a huge upgrade as well. I'd almost suggest you upgrade the phono stage first as you'll likely be surprised how much better things sound and then when you do your big upgrade you'll get the most out of it. That's a great table/arm/cartridge combo. I'd also suggest you look at clearaudio's performance DC table maybe with their tracer tonearm and a hana cartridge like the ml. The symmetry in that setup when I had it was trwndous. 

I've had a SOTA  star sapphire cocobolo since 1992. Works perfectly, never had any problems just twist the feet to level the turntable and enjoy.

No disrespect to others, but kindly disregard the advice of those who suggest that the amount you spend on a component (phononstage) should serve as the reason to replace a phononstage you already enjoy. Having been playing with these toys for 40 years, I’ve certainly learned that MSRP has no bearing on system sound quality in your room. 
 

You’ve identified an outstanding front end. Select a good phono cable (quite happy with my Morrow cable) and enjoy your system. But please disregard those who contend that you’ve not spent enough on your preamp. 

Concur and amplify the focus on the phono preamp then preamp first. My personal philosophy is that average turntables with good isolation is all that’s needed (It’s simply a level rotating plane - that’s all) - focus on the cartridge. Think Rega RP8 not 10.  Pro-ject higher model  from the Evo would do. 
 

I’ll diverge on constant upgrading of the phono stage though. Get a quality adjustable one with two inputs and call it good. I might upgrade one day long in the future - gold note ph-10 is absolutely amazing with XLR outs and the equalization (RIAA, Decca, Columbia) options are simply now table stakes for me. Applying the proper output equalization has such a meaningful impact it would take an article to elaborate.