pot size

hey everyone. i'm just about to start my grow room upgrade and i'm going to be growing plants to a height of around 1.5-2m (4.8-6.4 feet). What approximate size pots should i use so they don't get stunted or any such terribleness.

hydro, in coco. growing under 600 watt hps's

5 gallon maybe 3.....wait ur talking of hydro? im not very familar w/hydo so i dunno the pot size might be different than soil....anyone know if it is?

3-5 gallon would work good.

thanks a plenty