I have NEVER heard of a CA10 microphone from Chris church

You sure you have the correct name? There are CAFS/CA11/CA14 mics but to my knowledge, that's it. If you're not recording LOUD sources, then you shouldn't need a battery box or preamp before the m10. However I would still use a 9100 preamp for some extra, clean gain

and its still a TINY setup! I have a small camera bag you could use with your setup that would make it very simple to carry around, preamp and all

$10 if you want it. It's an unused lowepro bag and would fit CA mics/9100/m10 perfectly!