go for it i think they will do fine not to mention you will have thick budz all the way down her if you use lsting good luck
If you ran 4 trees in that space they would blow the fuck up with that amount of light! LST is good, and check out this pic of an LST plant,i love the ff stuff i still use the nutes with my coco just the coco is cheaper but deff better to have during flowering maybe i'll run 2 - 4 big trees got some bigbudxwhite widows coming thats what ima run
just start early to get the best results and a 5 gallon pot is fine but bigger is better in my opinion im sub'd i wana see the outcome good lucknever did the lst thing guess now its about time that i start