"MC phonostage" is too vague a term to make any reliable predictions as to how it may perform. Here a few possibilities as to what "an MC phonostage" could mean:
1) An op-amp-based circuit set for high gain (ie low loop feedback). Most of the mm/mc phonostages at the cheaper end of the spectrum are like this. They simply have a switch that changes a resistor value in the feedback loop to give higher gain for MC cartridges.
2) An MM phonostage with an on-board headamp. This type of design has a circuit for MM operation and an additional circuit before it to raise MC cartridges up to MM levels. The set-up you have now is effectively this, but in two separate boxes. The design could be all op-amp, or it could be op-amps in the MM stage and discrete transistors in the headamp part. Or it could use any combination/permutation of op-amps, bi-polar transistors, FETs or valves. My Rialto phonostage is an " MM phonostage + headamp" type and uses discrete transistors throughout.
3) An MM phonostage with on-board step-up transformers. These are less common because transformers are expensive, but EAR phonostages work this way, with valves as the active devices for the MM section. My own Signature One phonostage is like this but uses transistors in the MM section.
There are just too many possible ways to execute an "MC phonostage" to lump them all together and say definitively one would/wouldn't out-perform your current setup.
BTW, if you wanted to buy a different headamp there aren't many on the market - but I make one. It's called the Headspace
http://www.rothwellaudioproducts.co....c_headamp.html
Here are a couple of reviews from other forums:
http://audiokarma.org/forums/index.p...mbs-up.817174/
https://hifiwigwam.com/forum/topic/1...omment-2018258