5 Gallon bucket CFL , How big can you go?

Just a quick question for someone who has tried this...
Under CFL's (total lumens and watts up to question), what is the biggest you could possibly grow a plant in a mounded 5 gallon bucket?

I ask this because I currently have some that are about 1 1/2 maybe 2 feet tall in said 5 gallon bucket(s) under CFL's that i recently put into flower.
Probably going to stick to a soil grow next time as well, untill i have enough knowledge to go hydroponic. I figure the larger i grow these bitches up the higher my yield will be, I have a bathroom to my access with a ceiling about 9 feet up, IS this even logical to try and grow say like a 5 foot tall plant, if So, would i need like a huge rubbermaid for the medium, and how many lumens would be recommended of CFL's for something so large lol... Next grow I'm going all out... I plan on investing 75 percent of my profits from yeild this grow, back into the grow op.

I know most of you are already going to say get a HPS set up, I know i need to. but i just bought all these effing cfl's and sockets n shit the last few months and want to use them for a while.

I start my seedlings with cfl's . they are cheap , you can get almost 5k lumens / sq ft with 4 of them . make sure they are the right k . higher for veg , 4.5 - 6 k . I use hps for flower as the lumens per foot is going to be higher , but you could try and change out to the lower k bulbs , you are going to need mabbe 7 - 8k lumens per sq ft , sunlight is 10k approx. , height depends on strain , and how you trim it , scrog , fim . tie down . etc . I would get a 650w digital ballast when you can . I use a 1k but I lower it to 750 approx. ,