I use 1 , 2, 3 & 5 gallon pots.
If you use 2 gallon pots you will be able to put in 8, they will fit.
But if you are just starting out, I would encourage 3 or 5 gallon pots
(so you don't have a root bound problem your first grow)
Just try 4 plants in 5 gallon pots and you can veg them out...