I just bought a Denon DL-300 with upgraded Shibata III stylus on boron cantilever from virausa.com. It hasn't arrived yet, but I will try to remember to let you know how it is once it arrives. The price was very good. Fingers crossed it is better than my stock DL-300.
The company has its own line of MCs as well, but they are well over my budget. They seem to have garnered a few good reviews.
If you are ready to make the leap, then go for a step up transformer (SUT) and low output moving coil (LOMC). The reduced mass at the stylus tip, due to just tiny wires attached the the cantilever in stead of heavy magnets or chunk of iron, means that there is a speed in response and an improved high frequency response that make even excellent MM show their inherent problems.