The next upgrade should be a better table. I'd save up. You can get a notable improvement from one of the medium Regas, or should you be willing to go the used route, a Thorens off of Ebay (some reconditioning may be necessary, but these tables will blow away even the MMF-5). If you can swing it, the VPI Scout is probably awesome, but it's significantly more expensive ($950 w/o arm, $1500 with arm).
After that, the cartridge. I'd think about one of the cheaper moving coils, such as the legendary Denon DL-103 (available for about $160-200 from overseas dealers) or the new Dynavector 10X5 (probably $250 at the right discounted price), either of which will be a significant upgrade from the stock Goldring. Be aware that the Denon will require significantly more gain than your current moving magnet cart - I'm not sure whether your MF provides an MC stage. If not, you should plan on buying a step-up transformer from Jensen or Stevens & Billington. The Dyna is a high-output moving coil and won't require any more gain than an MM cart.
Hope this helps.