Analog Upgrade - Where to start?

BTW-Definitely get a SRA platform for the TT. The entry level VR is excellent and the up line is even better. The improvement is not small.

@rauliruegas @rauliruegas I recently purchased the Kuzma 4Point 9 to replace the SME Series V.  I have not used the Series V in some time.  The main reason for the change on Tonearm was that the Kuzma (and I know there are others) has a replaceable headshell.  My intent, along the line of what has been suggested on this thread, is to have cartridges with different sonic characteristics which I can easily switch between (I am not very “handy” replacing cartridges on the SME - the Kuzma much easier).  I did not notice much sonic difference moving from the SME  V to the Kuzma (the SME did have a somewhat darker sound, the Kuzma a bit more lively).  I also have the Koetsu Black cartridge that I have used with my current setup.  In my view it is much more musical than the Dynavector but rather less detailed and dynamic than the Dynavector.  
I have tried the Kuzma/Dynavector at gain of 60/66/72 dB and loads of 60/100/200/47k ohms.  I like the 200 ohm setting best as it gets me a bit closer to the sound I am looking for.

As mentioned I am a bit cartridge setup challenged (I am less steady of hand and keen of sight than I once was). The existing setup that I have was done by a the setup guru from the retailer that I purchased the Kuzma Tonearm from.  Consequently, I can shed much light in the protractor that was used as he had his own gear.  That said, during the setup process he tried many different variables with me to tune the setup to that which best achieved my sonic goals.

I've got a Herron Audio phono stage and line stage preamps, and I love the sound of both of them.... 

Your system is at a high level now - to try and extract even more - you are venturing into the trailing end of the graph and trying things that don't work any better - to your ear - would be quite expensive.

Do what I did - put in money to acquire more records instead.  And maybe some room treatment of it is needed.

(I run a VPI TNT V/SME V/ Koetsu Urushi/ Vendetta SCP-2D)

 I am looking to introduce more dynamic sound, detail (without edge) and musicality.

Put the turntable on a Townshend Platform, with Synergistic PHT Green and Black on the cartridge and ECT on the motor pod. 

Put your speakers on Townshend Podiums, and Synergistic HFT Speaker Kits on the speakers. 

These will absolutely deliver everything you are looking for, in spades. You will be shocked at the improvement, all exactly in the direction you want, at the ability to delve deeper into records than ever with tremendous detail and yet even slightly smoother overall than now. The great increase in musicality will be coming from the Townshend, that will remove a huge layer of resonance coloring the sound that when gone allows all instruments to shine with their natural timbre.  

You have good gear now but frankly will be shocked at how much performance is laying on the table waiting to be released. These will do it. Big time.