New Grower - Input Appreciated

Hey, I'm pretty new to this but I consider myself very knowledgeable.
I have this current setup:
-A home-made grow cabinet with inside dimensions of 16.5L X 28.5W X 25H (I know, small). I made the cabinet, and can open up the lid so that the light would not interfere with height up to 25 inches.
-2 20-watt fluorescent grow lights.
-Fertilizer for veg and grow stages that the local hydroponics store recommended for my SOIL grow (I am using miracle grow potting mix).
-I have a 90-watt UFO LED (VERY mixed reviews on it) coming in the mail.
-4-inch fan and Carbon filter
-Also, I am going to purchase either a 400 or 600 watt HPS setup from my local hydro store, and I will use this once I get it.
(EDIT) I am using seeds I got out of a qp of purple buds I bought this summer.

I plan on getting a grow tent/making a larger box, but that is what I have to work with.

So, how can I get the most/highest quality yield? With what I have/what I have arriving, what setup is the best? SOG? SCROG?

Also what is better for yield, one large plant (it would probably have to be low-stress-trained), or many small plants?

With this in consideration, what do you think my grow plan should be (veg for how long/until how tall before flowering?)

How much can I expect to yield from this box (I know....so many factors, blah blah blah, but my lighting and nutrients should be optimal - it is just a size/setup issue).

Man you aint workin with much yet.. I'd be focusing as much attention to that tent and HID as possible because that's were your sizable yeilds are gonna come from. For now; with that space and cfl lights, I'd just go for as many plants as you can cram in there in party cups and just start em on 12/12 so they bud as soon as possible. Don't let em bush out man just focus on the top colas and get quick harvests for fast turn-arounds. the longer you veg, the more they will outgrow your boundries.

Cool, yeah I actually went to the hydroponics store today and I'm picking up my 400-watt the day after Christmas (I'm going out of town and as SOON as I get back I'm buying that motherf***er). It's gonna set me back a few, but from what I've researched, it will pay for itself pretty quickly.

Any recommendations on grow tents? I live in an apartment and I don't want a huge operation.

Also, is the general consensus that for this size grow box it is better (for yield, anyway) to have many smaller plants?

Indeed it will. I don't have much experience with tents. If you find a closet that you'de be comfortable growing in I will answere any question you would like. All I know is that you have to either utilize a decent grow space with that 400 watt, or vent the shit out of a small one cuz dat bitch gonna get hot!

Hey guys, here's pics of one of my plants. They are currently under 334 watts CFL (I have more in the box, but I am waiting to turn them on until I can kill some of the plants and free up space...long story....).
Anyway, how does this look so far? I can't tell what sex it is, it has been under flower for a week. Have topped it twice, and LSTed it, so it's pretty bushy. I hope its a her!!!
I just watered it (her?), so it might look a little droopy.
I have more pics if you need them, if you are looking for anything specific I can take them, (as long as it's before their bedtime -

Is SHE a SHE?
I hate waiting on sexing. This sucks.