Phono (0.1- 0.22mV+) or step up for LOMC?

The KAB calculator is your friend. In my experience, unless you are using a passive preamp or have a pretty unusual system in terms of extremely high efficiency/low efficiency speakers, or very low powered tube amplification, the KAB calculator should give you an almost exact read of proper gain as it relates to output of the cartridge.

In the price range of phono stages that you are considering noise issues should be minimal or non-existent if gain is matched properly to the output of the cartridge. In addition to that, you should be achieving the best possible sound with proper gain matching. It is very important.

Use the output section of the calculator to establish the correct gain level for your cartridge and the sensitivity section below that to input the sensitivity of the phono stage to establish how much gain it is providing on the MC input.

http://kabusa.com/frameset.htm?/

If you want to go the step up route you're going to need an extra set of IC's and you're going to have to do further/a different set of calculations. It would not be my first choice but it's a subjective hobby. My preference is for a versatile phono stage that offers flexible gain options to suit a range of cartridges. 

Korakotta:

There is always a propensity on audio forums for advice that involves change and spending more money.

I can understand fully your preference for running balanced, especially if you have been able to hear your MF phono pre in fully balanced mode. I’ve been running fully balanced on the analog side for 10 years now and there will be a performance enhancement with most phono preamps running balanced vs. single ended with low output moving coils. There can also be a pretty significant lowering of noise levels moving from a single ended input to the balanced input on many phono preamps and it appears that this is exactly what you experienced with your MF.

From the sensitivity spec of your MF phono preamp it would appear that you have about 56-58 db of gain. In most balanced phono preamps, running fully balanced in and out of the phono stage will give you an additional 6 dB of gain. It is not clear from the MF specs whether this is indeed the case-I would recommend that you contact MF and see if it actually is and get their thoughts on running with a .2 mV cartridge. If there is indeed an additional 6 dB of gain running fully balanced in and out, the MF should be a very good match with your cartridge and require you to do nothing more than properly terminate your tonearm lead with the necessary, albeit a bit unusual MF balanced connector.

It sounds like you were able to source an appropriate tonearm lead to audition your MF phono pre in balanced mode before. Would be great if you could do that again with your existing cartridge.