Your choice - TT, Arm, Stage, Cartridge - $5000 budget

whacky-with the equipment you have, it's clear you want maximum performance and value.

"For sound,I like the idea of a balanced overall sound, and a big soundstage. But what I really enjoy most is the idea of exposing the holographic image in a recording."

Everyone desires those attributes. If I were in your position, and serious about playing a record, consider a proper used phono stage. Something that retailed @3-5K, find for half. Up your budget for table(used) 3-4K will get a killer table. Spend 1k for a LOMC 

You will now hear what the fuss is all about. Been using the PL HP for a few years. 
A used VPI Prime/1K LOMC and used Allnic could be had just over $6-7K?

Good Luck

The Asylum is  another option, but much smaller scale.
Audioshark, I believe has a classified section.

Ive had good luck here. Do the legwork, and you'll find deals waiting. 

"Whats the general consensus about a tube phono stage?"

whacky-you have a great tube amp, finish it off with a great tube phono.
Heres one 
https://www.audiogon.com/listings/phono-allnic-h-1201-in-silver-face-2017-07-13-preamplifiers 
I would ignore the asking price. Brush up your negotiating skills.
 
You can find a Manley Chinook for $1500 with patience.

Someone else may chime in with other bargains.

"The VPI Prime seems like a very attractive option for the price it can be found for right now. Really on the verge of pulling the trigger on this one."

whacky-that VPI listing is a good deal. Offer $2200 WITH shipping, 2-300 will buy a cover.

I paid $2500 for a new VPI Classic years ago, and the Prime is a notch better than the Classic. Nicer arm, on the fly VTA. just a better table all around.

Plug that into whatever tubed phono with an ART9 or other LOMC, and you're done. You will have a system equal to a $20K+ new retail rig. IMHO of course.

whacky-IMO, a good score w/cart.

Mission accomplished on the table end. Good luck on whatever you decide phono stage.

Edit: considering we have the same amp along end results, I would look at maxing your budget on the phono. If your final choice is a tubed, I would go in no particular order:Allnic,Herron,Manley,Zesto....etc.Someone else will add another amp.

 Saving a few bucks:Manley Chinook, Fosgate V2.....etc..  Under $1500

"That being said,I still dont know how I feel about buying carts on the used market. Seems like a great way to save some cash if the situation is reasonable. Dealers, low use, well maintained, etc."

whacky-
In most cases, I've read positive outcome regarding used carts. Whatever phono stage you end up using, the Cadenza seems to be popular regardless of paper specs indicating otherwise.

Being out of major acquisition mode, it appears there are great deals out there. More quality choices  than when I did the  jump to "proper"  gear.

"So the last piece of the puzzle is the cartridge."

whacky-you're  almost there. Hope that phono stage works well with whatever cart you decide on.

Cart selection is a drag. After using  a few popular MC carts, I've found a keeper that many here like-Audio Technica ART9. Under $1k and used by a few Prime owners.

If your new stage has 65-70dbs gain, a possibly more refined cart is the ART7 for even less $7-800, but only online. It has less output so you need a little more juice than what the ART 9 requires.55-60 DB's 

whacky-

I’ve used the following:
Sumiko Blackbird-overall nice sonics,but sometimes a little too much detail on the upper end.
Benz Micro Glider-too warm for my tastes,soft overall presentation discontinued now?
Audio Technica OC9III-great budget($500ish)MC, but shrill at the upper end, which was wearing.

These see traits may not be heard in other users systems/ears.

Check this thread out on the ART 9-
https://forum.audiogon.com/discussions/pani-new-art-9-up-and-running

The ART9 on my VPI Classic, thru my tubed phono, presents itself as a "goldilocks" cart. Not warm, not bright, just....
I would love to try several carts, but they are all $2K+!!
For the level of gear I have, the ART9 makes my system sing.

I wasn’t familiar with the Whest, after taking a peek at the website, looks like fine SS gear. I noticed they list the ART9 and AT50 as some of their test carts for their phono stages. That’s promising.

Your model has been superseded with the 40, but the specs are generally the same, so you have enough gain to consider an even lower output MC like the ART 7, which go for a couple hundred less.

Good luck weeding out the contenders