2¢
Unfortunately, you are looking to outperform your phono pre with any other change you make. That's not what you wanted to hear, but it's true. Be prepared to do an upgrade there soon if you go with a lp12, which will also require a better cartridge. $10k later and what do you have? Maybe a better system, maybe not. You have built a nice system. Enjoy it and let the upgrade bug bite someone else. Buy more records, maybe a modest cartridge.
The most significant component improvement you can make is your room. If that's taken care of, then sit back and enjoy.