I'd go for 5 gallon pails. Drill many large (1/2-3/4") holes in the bottom AND SIDES. Let the root ball dry out pretty well before the transplant. This will make it LIGHTER and less likely to break apart under its own weight, as well as just slipping neatly out of the pot.
Transplanting is not stressful if you follow those basic guidelines.
I wouldn't try to switch soil to hydro though- THAt is stressful!
For side lighting, I don't recommend CFLS under the canopy because they are hot and can dry or scorch leaves. But a 2 foot flourescent fixture with a daylight T12 tube in each corner of the box would be just peachy! T12s run very cool and can be in extended contact with leaves with no significant damage.