At leat some of the different version are the same cartridge with different styli for different applications.
For general information, pre-Stereo LPs had different groove sizes, the further back you go, the more variance. Using a variety of sizes and shapes can get you much, much better signal to noise ratios on old records.
The most important one to have a 1 mil to get dramatically better sound from the many cheap reasonably good recordings of the fabulous performances of the 1950s, like mono Dogs. That's probably the only alternate stylus you need if you only play lps.
If you play 78s, you need at least one "78" size, like a 3 mil, although in practice there are many sizes for different eras and different brands, as well as different shapes so that you can ride the groove in the area with the least wear.
The Stanton 500 has been around for decades, is still widely distributed, can handle higher tracking forces needed for old recordings or broadcast work (but maybe is not ideal for the dance floor), and its really easy to swap stylii on it - they slide right in and out. Stanton makes an inexpensive 78 stylus, sometimes makes a mono stylus (may not be currently in production), and there are aftermarket stylii available in many sizes and shapes, although those are kind of expensive. In fact, there's even a device that you can slip into an Edison cylindar player that holds a Stanton 500 where the "floating jewel" would be so you can get an electrical output to tap.
Certainly you can enjoy the music with a Stanton 500 -- as quite a few people did in the 70s, and for that matter, with the turntable you have. However, I would not use a 500 as my main cart today, unless you're someone who is just breaking into vinyl and find one on a used Dual, Elac, or certain Garrards, and you clearly are not. Certainly there are cheap quacking cartridges that are worse, but my clear preference on a budget would be a Grado, and my slight preference would be an Ortofon (I have not heard the Oyster or the low-end Goldring which may also be good choices). If you move beyond the cheap, there's no contest.
Good luck. Let us know what you end up doing.
I'm trying to get some info regarding this turntable, i've been using it for the past decade or so, changed the cartridge once to a Stanton 500, if anyone has any links or any info, i would appreciate any info, i'm wondering if its worth upgrading to a new cart or just buy a new turntable. 
