recommendation for a high end analog system

Sound lab speakers are FANTASTIC, so I don't think my weakness is the downstream components. Everyone is giving great advices. Ideally I would upgrade both the cartridge and the tonearm. But changing the tone arm on a SOTA TT is a lot more hassle, with no SOTA dealers around me. So, the cartridge upgrade is probably easiest to pull off not to mention the very high price of a top notch tone arm like Triplanar.

One option is to buy another system (with a better arm on it) and sell my current system. What do you think? I am thinking that a VPI TT with VPI JMW 3D arms may be a substantial improvement over my Sumiko. Of course, VPI TT don't have the vacuum, but I don't know how much real benefit I am getting with the SOTA vacuum.

@chungjh

I wouldn’t be on scared to change your arm. The biggest thing is getting the pivot to spindle correct with your existing arm board, or get another from SOTA as/if necessary. 

Then, balancing the new arm with the suspended sub-assembly using the correct amount of lead shot weight.

lol, I know that sounds like a lot, but really, it isn’t so hard, and you will quickly understand how the SOTA works by doing this yourself. That is how I learned, by simply doing it. If you need instruction on this set-up, they can probably be found on-line, or, again, I’m sure SOTA would be willing to email you a copy.

@bkesk, What tonearm and cartridge are you using on your SOTA?

@chungh 
I hgave owned the Sota vacuum and am very familiar with the TT and the Sumiko arm.

In my view before you look at cartridges, you will get a better result if you do the following -

Step 1 - get the Sota brought up to current spec - Sota will do this - their service is excellent
Step 2 - upgrade your tonearm - buy the best you can afford. Sota can provide either blank or predrilled amrboards. You will have to choose a 9-10 1/2 " arm to fit the Sofa - Sota can confirm what will fit.

These first steps should improve your system markedly and set you up for a very long time.

Then Step 3 - you can start looking at cartridges down the road knowing you will get the best out of them with the updated turntable and tonearm. A great arm with a modest but good cartridge will always sound fundamentally better than an expensive cartridge on a cheap arm.