MGM controller do I go for amperage or cell count??

[Purplefade]

OK here's the question, I'm in the process of puting together my Savage and am "concerned" with using an ESC to its bleeding edge... My Savage will likely be in the 12 to 15 pound range loaded with cells and ready to run and I'm planning on a 10\12XL for the near future and upgrading to a Nue 1515(not sure which one yet) when cash permits. My target voltage would be 19.8 (6s A123) to 26.4 (8s A123), do I go with the MGM 22418 or the MGM 16024??? I realize with higher voltage and the right motor you effectivly pull fewer amps, load to load, hum... which one to buy??

I also thought about saving myself some green and going with the MGM 16018. Not to mention this solution puts me closer to my NUE!! My concern with the MGM 16018 is that it's only rated to 6s, can I sneak by using 8s A123s with it, anyone know?

Figured I'd poll the cumulative brain power on here before making an expensive mistake :-) :-)

Thanks!!
purp