best type of light for space

Hello ,
What is the best type and wattage light for a 18" x 18" x 48"H room? I have a small compartment attatched to my GR. Wanted to do a small SOG.
Also , what size containers should I use , I usually use 5 gal , but obviously they would not fit.
Thanks

i would go with florecent tube light but not sure how small they make them might have to go with cfl bulbs

How many plants are you looking to get in there and will you have good air flow?

Wanna get about 12 plants in there , just for long veg till flower room is empty and I can transplant them and move them over.