I think getting your SOTA tuned up and back to snuff is a great place to start. Ditto with keeping the PS Audio integrated. PS Audio was particularly good with phono stages, and a lot of mid-'80s phono gear was really good, Amber and VSP Labs being a couple other good examples.
I was going to suggest a pair of Sequerra Metronomes (plus a little powered sub) from Acoustic Sounds to replace your Vandersteens, but it looks like they're not selling those anymore.
I was going to suggest a pair of Sequerra Metronomes (plus a little powered sub) from Acoustic Sounds to replace your Vandersteens, but it looks like they're not selling those anymore.