MM vs. MC

If I was looking at a Grado Reference Platinum cartridge, to be played on a VPI Scout & JMW9 tonearm with a Musical fidelity phono stage, How high a quality MC cart and phono stage would I need to better the sound? I have ordered the Scout but am strugling on the cartridge, is MC better?, and if so is the high output MC better than the Grado Platinum, or the Grado Sonata. I only have so much cash, the VPI was $1500.00 the Qunex 3 cable was $150.00 so I have $800.00 left this go around. Any suggestions on the cart, would be great, I have an internal phono stage in my X-150 but it's an MM with 2.5 mv so a lower output MC would require an external phono stage, if this is the way to go, any suggestions on a low output MC and external Phono stage for $800.00 that will be better than the Sonata through the X-150....Help!