Decent combo amp?

[Jim Carr]

...Liking everything I can read about the GK MB200 and Neo 112 II. Plan to add a second cab, either another Neo 112 or a Neo 212.

Adding the 212 cab would give me three distinct configurations of a single 12", dual 12"s in a single cab, or a three 12" mini-stack for larger venues and maybe a rounder, fuller sound (?) Thoughts? 2nd question - Should I consider the MB 500 instead of the 200, particularly if driving the three 12" configuration in a larger venue?...

I recommend the mb500 over the mb200, based on the principle I have proven over and over that "too much is never enough." I have an mb800.
About the cabinets, I think there are a couple of TBers using something like the 312 two cabinet rig you describe. Just be sure of two things: the impedance must not go below the minimum of 4 ohms for the GK mb series, and that driving two dissimilar cabinets (112 + 212) don't leave you with a fried 112.

IMHO, you would be better off with two 112 or two 212 cabinets. Have you considered building light 112 cabs from a kit? There are 12/6/1 fEARfuls that might float your boat and two of those = a conventional 412.