Kiko and spanish are also considered meat breeds, I think fainters as well but the boers are kind of the main ones, at least around here.

There really isn't an average amount an average goat will milk. I've seen full size dairy goats milk as little as a pint at peak (per milking) to as much as 15 lbs per milking. It seems depend on a combination of genetics and feeding, disease concerns aside.

A gallon a day is considered fairly good. I shoot for a gallon a milking with mine. I think much more than that puts too much stress on the goat and her udder and it seems to be what I can have my girls easily produce on my pasture. If I want that much more milk, I'll get a cow.