First off, welcome. I'm still kinda new here too. Great board.

Now the bad news--no, you aren't going to have enough light for 5 plants, at least not in flower. I'm not sure if I'm reading your grow space right...20 sq. ft. is pretty huge. We're talking about needing 100,000 lumens huge. And it's way more than you'd need for 5 plants. 8 sq. ft. would be plenty for five plants; 6 is plenty for four plants.

Five 2000 lumen bulbs will give you 10,000 lumens, which is enough to do a very good job on flowering 2 sq. ct. and a fair job on maybe 2.5 sq. ft. That's enough for, maybe, two plants. But that's just talking about flowering...all the leaf/flower areas really need light then. When you're in veg, the plants are smaller. You can get away with less. You can veg six plants under 150w of CFLs...you could fit six 5? pots into a 15? x 10? area. It would probably be good for a few weeks. But if you plan to flower six girls, you'll definitely need lots more light. And, yes, with CFLs, it's nice to have a few down low for under canopy penetration.