Well as far as mah I wouldnt go lower then 5000.
I run thunder power 5300mah 65c 2s batteries and really like them.
Downfall is they are $120 but you are paying for name and reliability.
They pack a lot of punch.
I was gonna go gens ace to but with out of stock for months and the risk of blown cells, i think I will stick american.
If you are willing to wait a couple more months im sure you will be happy with them if no bad cells show up.
Just my $3.26 worth