The in-game recharge time is several seconds, but that could easily be fudged up to a couple of hours, I imagine, since the house already messes with technology.

There's no hard canon as to how big a single "dose" of medi-gel is, or how many doses suit compartments can hold, but similarly, it would be easy enough to decide on a suitable number (I don't think it would be very high, considering the suit has pockets/tubes/containers for a lot of things, and weight limits would eventually be an issue).