Thinking About Purchasing a New Camera

I have the Sony 70-200 2.8 G series lens that is amazing, but even for night games the pictures get very noisy at ISO 1600.  The A99 has a better rating up to 3200, but the Mark III has an even better rating up to 12800.

When I shoot a game that rolls past dark I can't really get any good shots for the last few innings.