How many plants for a 2'x3' closet? Maximizing yield?

Hey Guys!
Not a complete newb, but i'll leave this here for others to see.

After a few year break, i thought i'd throw in some old random seeds found in the stuff i had smoked. 16 seeds, all 5-7yrs old, threw straight into soil, had 11 sprouts, 8 healthy plants.

Room is a 3' x 2' x 6' closet, atm using 250W MH. Week ago replanted from cups to 3/4 gallon pots. Plants are 3 weeks old and growing nicely.

Right now they're 5''- 8'' tall, min 8'' wide, with 4-5 nodes. The little ones are previously stunted seedlings, just keeping them until there's space, flower under CFL for some minibud.

So obviously the number of plants per area decides how they're grown. So which is best for these plants in a space of this size?

What i need to know:
- Max number of colas per square foot with lst (how tight can you pack the room)
- Maxing yield given the dimensions of the room (esp height), but also "sweet spot" of the light
- How much airflow required to up to 400W HPS, is "cooltube" mandatory (right now temps around 26-28C, measuring spot on photo, vent outtake at the top and passive intake at the bottom, outer temperature ~18C)

Stick to 1/sqaure foot, chuck the smaller ones, take clones of the ones you want to keep a week before you flip.
Root and veg them in another setup to be ready for a perpetual run.

1/square foot does that mean you full on SOG it, no topping/LST? The few grows i've done i've always ended up creating trees, never done so many plants in a little space.

1 plant. Mainline it.

I usually figure on about 4 square feet per plant. With just 6 square feet I see 2 obvious choices.
1. Get a short bushy indica and top or FIM her at 10-12 inches. Or,
2. Try 2 autos set side-by-side.

I would go with #1 because I know indicas better. Advantage to #2 is that autos usually give you a single main cola, thus using less space.

I would also look into getting a larger growing space, a bigger tent would help or simply kill the tent altogether.

Good luck, BigSteve.

4 sided vertical net would more than quadruple your canopy size and yield. Not enough space though so a stadium style

SOG. Proper strain. Bloomed at 8 inch's.
12 plants = over 12+ zips.
1 gallon plant warrior pots, feed properly......COB led set up....