When comparing the Menu Cs to the Meal Kit Supply MREs, you could probably reference this page:
http://www.mreinfo.com/civilian/mre/civ ... rison.html
and substitute the words "Sopakco Sure-Pak 12" for "Meal Kit Supply MREs". While they're not 100% exactly the same, Meal Kit Supply does get their MREs from Sopakco and with the exception of some of the meal selections, they're close enough.
The other place where the Sopakco and MKS MREs will differ is in the pricing. While you can find Sure-Pak 12s for US$70 or so in the US, MKS MREs have a different price in Canada. You'll have to check for yourself to see if it'd be cheaper to buy, import, and pay duty on Menu Cs vs. just buying the MKS MREs locally.
As for the contents of one vs. another, I'm pretty sure the Menu Cs will have more food in them...but probably only by a snack item or two.
I'd recommend comparing the menus, comparing the prices, and then pick the one that works best for you. I'd be interested in hearing what you decide on.