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

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Your model has been superseded with the 40, but the specs are generally the same, so you have enough gain to consider an even lower output MC like the ART 7, which go for a couple hundred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

You can get a Technics SL-1200G for $3995.00
You can get a Cart and Phono stage for about $1500.00 A bit more but amazing.

I also have Luxman PD-171 with a tonearm and Koetsu cart. Store Demo at $5500.00
I also have VPi Prime with a fantastic Audio Research Phono Preamp and cart package for reasonable money.
626-966-6259.
www.sunnyaudiovideo.com

In terms of going second hand you have a wonderful selection available. 
For a 'big stage' a good phono stage is essential. I had an EAR 834P which has that big stage you are looking for. I own the original Whest phono stage on which I did a review over 10 years ago.
As to turntable... I think one of the widest soundstage you will get is the Michelle Orbe (famous for its wide soundstage) which is a great piece of kit and very arm friendly - a modified rega is often a very good buy. 
don't discount the idea of a good MM cartridge - they give a very bold full bodied sound and place less demands on a phono stage - raulrigas did a very long thread on this topic. I have an old Pickering that I got with a second hand Townshend Elite and was astonished with its' performance - very full bodied. Consider the Denon dl103 as well.

First and foremost, if you are new to vinyl, you need a pro to come to your home and set up your table for you. It should cost between $100-$200 and will be the best investment you can spend as far as turntables go. Having a pro set it up at the pro's shop is second best assuming you don't mess it up when you remount the arm onto the unipivot spike of your Prime, lose the counterweight setting, etc. I own the Prime and have had various Benz and SoundSmith cartridges mounted. I recently had my dealer install the dual pivot ($150) and an Ortofon Quintet Black and it has never sounded better. I have the 3D soundstage now that you have mentioned you are looking for. The Benz's are second best and the SS's a distant third in that category. SS's excel at lively dynamic punchy sound throughout the audio spectrum. The Benz's excel at detail and clarity. The Quintet Black with a well recorded record is the most organic, real-sounding of those that I have tried. Eventually you will want a top phono stage but it can wait. A used Simaudio 310LP or SimAudio LP5.3 or even a new iFi iPhono2 will give you years of enjoyment until you find the dream phono stage you can afford. I went this route (SimAudio Moon LP5.3) and eventually bought a Manley Steelhead that had about 5 hours on it for a very nice price. I've had a ton of phono cables in and out of my system. I had a slight hum problem. I just took a flyer on the Morrow Ph4's with Eichmann plugs because they are well-shielded and despite their veery reasonable price, my hum went down by 80% to a very low level and the SQ is incredible. Whichever phono cables you choose, make sure they are shielded between the Prime and your phono stage and between your phono stage and preamp.