Happy with digital, but thinking about vinyl--looking for system specific recommendations

Since your phono stage apparently has gain enough for an MM or MI cartridge, but not a LOMC (Low Output Moving Coil) type, I would recommend a top notch MM or MI cartridge. Sound Smith make a line of MI cartridges that have a good reputation, but you need to be sure the output voltage is sufficient to drive your MM stage. (MM cartridges generally put out about 3 to 5mV at the standardized stylus velocity of 3.54 or 5.0 cm/sec. Whereas MI cartridges often produce closer to 1-2 mV at the same standard velocity.) Nagaoka, Grado, Clearaudio, Audio Technica, and others I cannot conjure up at this moment make fine MM cartridges. I use any of several "vintage" MMs, including Grace Ruby and Acutex (which is actually an induced magnet type). I am currently comparing my Acutex LPM320 to a newly acquired Audio Technica ART7, which is an LOMC type. The ART7 is very highly regarded, and I like it too, but the Acutex gives away nothing to the ART7. Lately, I am tending to prefer the Acutex, but the ART7 is not fully broken in.

Here ya go! Under $500!
https://www.needledoctor.com/Rega-Planar-1-Turntable

The least expensive option may not give you what you want. You could look out for a used vintage table like a Thorens 160 or up your budget to a Rega 3 etc. 
I have a few Croft amps including a 25R. I would strongly recommend swapping out the stock tubes for Telefunken ECC83 or Shughang 12AX7LPS black. Nagaoka MP110 is a good starter cartridge. 

Thanks for the opinions so far. Maybe I shouldn't have mentioned least expensive, and instead said a good value that matches the rest of my system.  From what I've heard, I agree that a Rega 1 is probably not quite there (though it was in a more entry level system than my own).  

@noromance 
I'm currently using some 60s RCA tubes in my pre instead of the stock.

@gnostalgick

What is your budget, ballpark?