Joining the Milwaukee cordless universe

I think the 5.0ah batteries are fine with impacts and drills but my angle and die grinders run them down real quick. I have not tried any of the big high output batteries.
 
Do you need ti buy the 12ah separately or do they come in some tool package. The selection of tools and accessories from Milwaukee is mind numbing. With the high prices they are asking I want to make sure I spend wisely.
 
Do you need ti buy the 12ah separately or do they come in some tool package. The selection of tools and accessories from Milwaukee is mind numbing. With the high prices they are asking I want to make sure I spend wisely.
They do come in some of the high demand tool kits.