If I were to grow again and had the space I wouldn't use less than a 5 gallon container. I saw a grow where the guy planted half his grow in 3 gallon containers and half in 5 gallon containers and the ones in the larger container smoked the others in yield. Everything was the same for all plants except for the size of container. Only thing you'd have to watch and adjust is your watering schedule and volume as of course a seedling won't take near as much as a mature flowering plant.

To me, if you had the space, the answer would be to grow in Jiffy Pots (the ones that break down when placed in soil and the roots just grow right through them) and then put them in the 5 gallon container after a few weeks. And that time frame of course dependent on the size of the Jiffy's. No transplanting needed.