Analog Upgrade - Where to start?

The rest of my system: Pass Labs XA60.8 amp, Audio Research Ref 6, Avantgarde Uno speakers, Silent Source interconnects, Audioquest power cables.  The kind of sound I am looking for: dynamic speed/without the hardness, fullness/rounded/balanced, musical (sounds like real instruments/voices nothing added and nothing taken away), wide/deep soundstage, revealing but not at the expense of musicality.  

I would like to thank everyone for the great advice and input.  It’s been very helpful and further confirms to me that the turntable and tonearm do not need to be changed.  
Some people have mentioned that there is a place to list out system components (perhaps  in my profile).  I will try to figure that out and update it.

I am not sure it will help the discussion much but the PS Audio Stellar Phono stage replaced a Tom Evans The Groove (from 2003).  I was happy enough with the Tom Evans though there are certainly much better phono stages mentioned by members on this thread. The reason for making the change is that the Tom Evans met an untimely end at the hands of a young family member.

One problem I have had selecting cartridges in the past is that nobody seems willing to let you do a home trial … I can understand why. Each system and room is so idiosyncratic that I don’t see how you can select a cartridge without trying it in your system, especially those +$5,000 cartridges.  That is a lot of money to spend when you can’t know how it will sound in your system/room.  How do you overcome this?

@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.