Best way to spend my money

No idea what the heck you are talking about sorry 

Shame the reply is dismissive, the Digital Guy maybe has quite strong ideas for analogue and is quite sure of where they expect better things to come from.

The only request for info in the Post was the following,  

"  Making more known about how the TT is being supported will help with making suggestion for mounting the TT, that can return substantial benefits. "

Is not 'can return substantial benefits' very similar to "expect better things to come". 

I'm not sure where benefits or better is on the table without considering the best possible mounting for the TT.

Good Luck from here on, it will be very very easy getting what other suggestions to be offered are talking about. Take the usual advice to be put out there and see how a Bank Account will be encouraged to drain very very fast. Usually where required funding is ascending fast to 10 x $1K, this is not unusual on the Gon. Some members won't even try and help with only $1K to consider, that is how much the connectors on their to be suggested Cable are intended to cost.   

You have a pretty good set up already.  For my money I’d invest in a decent set of balanced cables.  That long of a run in RCA cables is asking for trouble with noise. Especially coming out of a phono preamp.  All my source equipment is 20 feet away from my tube power amps.  I use XLR for the long run from my preamp.  I have zero noise using those cables.  

+1 @winoguy17 

Maybe a new rack that will hold your TT. 15' RCA run seems long for TT.