Richmon, I'm with Johnnyb53. You have a very nice phono-pre, and from what I can tell from other threads, a nice set of speakers. It would be a shame to be turned off vinyl because you don't think it does well compared to your digital (which will probably gain some 'smoothness' because of the tube output stage vs an op-amp output stage in other CDPs). If you need to stick to $500 for table+arm+cart, you will be woefully 'undercutting' your system's capabilities, but it can be done. If I "really, really wanted to stick to $500" (+ shipping), I would 'cheat' and be flexible :^) Otherwise, I would go for a table older than either the Rega or the MMF - you can get more bang for buck with an older table (the Denon DP72L mentioned below listed for $400 (and sold) today is shown as having an $800 MSRP but that was 25yrs ago and that table had 15yrs of motor technology built/amortized into it by that time). There is an Empire 598 offered at ~$600 and a Lenco L78 listed for a lot less, both of which would be vastly improved by a better plinth at some point (not to mention better arm, though there are some who like the Empire arm). There is also a VPI HW19 and a Project RM-5 listed in the area of $500. Finally, the Technics SL1200 is a pretty darned good deal (though some will not like it's "DJ-style" looks. On a used basis, you might be able to get a KAB-modified one for your budget, otherwise I think a new one would come in under, and then you'd have to add a cart.
If the arm you end up with is on the heavy side, I can recommend the Denon 103 cart, which should be available for around $200 new.
If the arm you end up with is on the heavy side, I can recommend the Denon 103 cart, which should be available for around $200 new.