4x4 optimization

I am ready to begin the next grow and I am interested in some of your opinions on optimizing my 4x4 table. I have two 4x4 tables and previously I had hung a digi 600w Lumatek over each table (one light per table). Now I have decided to hang both lights above one table and have bought a 4 light t-5 setup for the other 4x4 to veg (less down time, yay!). I am wondering how many G-13 clones I should grow on the table to get the best yield out of these "stretchy" plants. I am a "topper" and occasionally tie down. I really want to address the following:
Grow Bag size - Usually use 3 gallon but should I use a bigger bag and grow less plants or go go smaller and use more clones (clone supply not an issue)
Space per plant - I am considering using a SCROG but would prefer not to. Would 1 sq ft per plant (16 plants, right?) be optimum under my conditions?
By my math I have 75w per square foot (600w x 2/16 sq ft); this time I am also supplementing with Liquid Light (1st time trying). Do I have enough PAR or lumens/sq ft under my setup?
If I left you the supplies, clones, lights, how would you arrange the plants and how many to achieve the best results? FYI, I have had 8successful grows in soil and 1 hydro. I want to remain in soil, but can go soilless if it is the consensus that it would be the best way to go. Cant wait to see the responses!

Yo. Sounds like you have a very good handle on this stuff already... here goes!

I have two 4x4 tables and previously I had hung a digi 600w Lumatek over each table (one light per table).
That's the correct light for a 4x4. Add efficiency with the best bulb/hood you can afford.

Now I have decided to hang both lights above one table and have bought a 4 light t-5 setup for the other 4x4 to veg (less down time, yay!).
Yes, you are definitely cutting down 'downtime' but according to the rules of nursery supercropping, your use of light could be more efficient... I'll get to that later. Hang on...;)

I am wondering how many G-13 clones I should grow on the table to get the best yield out of these "stretchy" plants. I am a "topper" and occasionally tie down.
Okay. Here's how I'd do it. Take your clones, root them. At the end of the 2 week rooting period, pinch the very tip. Plant in ~3" pots of your preferred soil or soilless mix. Put under your flouro fixture in your mother room under 24/0 light for the 2-3 weeks necessary to recover from a pinch. THEN transplant into your grow bags and put into your flower tables.

I really want to address the following:
Grow Bag size - Usually use 3 gallon but should I use a bigger bag and grow less plants or go go smaller and use more clones (clone supply not an issue)
I'd use a 2 gallon bag personally, with clones transplanted into it after 2 weeks' rooting and 2 weeks' vegging. 3 gallon is fine.

Space per plant - I am considering using a SCROG but would prefer not to. Would 1 sq ft per plant (16 plants, right?) be optimum under my conditions?
Yes. I think 1sqft is perfect for what you describe. Don't go SCROG since you aren't concerned with plant count. Plain ol' SOG is perfect. Pinched as described above, you should aim for 2-4 healthy leads per square foot. That gives plenty of exposed terminal budding sites, yet allows air flow.

By my math I have 75w per square foot (600w x 2/16 sq ft); this time I am also supplementing with Liquid Light (1st time trying). Do I have enough PAR or lumens/sq ft under my setup?
I'm SO not a numbers girl.. :( lol

If I left you the supplies, clones, lights, how would you arrange the plants and how many to achieve the best results?
Yay, my favorite type of question!
-Leave the 2 4x4 tables as they are with your sexy 600digi over each.
-Stick the T5 (sick fixtures btw, love mine) in your veg/clone/mom area and use it for one table's worth of new clones every month. When you get the clones rooted and in 3" pots, you can just leave them there under the light until a table opens up.
-Take ~25 clones per month and cull the weaker ones, or the ones that don't seem to respond well to a pinch at the end of the rooting period.
-Keep 2-4 large mothers that can provide you with a total of 25 clones per month.
-Expect to stagger the tables to harvest one per month. This makes your trimming job easier lol. If you only have one res, forget it- just do full 2-table SOG 2-month cycles, and take 50 clones every 2 months (at the beginning of week 3 of the previous batch flowering) instead of 25 every 4 weeks.

FYI, I have had 8successful grows in soil and 1 hydro. I want to remain in soil, but can go soilless if it is the consensus that it would be the best way to go. Cant wait to see the responses!
Promix is easy for a setup like yours where plants only live in their bags for 8 weeks and don't have a chance for the mix to sour on ya. It's soilless. But any high quality medium is fine as long as you match your ferts to it correctly.

Hope that helps some? Happy growin.

One light or two lights will work. Either setup will provide adequate light for growing. One plant per sq. ft. is great. I've used the liquid light during veg. for the past two weeks. Can't see a difference between those sprayed and those not sprayed. Will be transplanting this weekend and I'll check to see if those sprayed with liguid light have more root development.

I've also been running some of my vegging plants with a new product called 'Vermablend". This company was selling setups to hydro shops to brew their own 'tea'. It never got off the ground because the tea had to be used within a day or two and you can imagine the headaches of no shelf life. Customers would have to come in on a certain day so they could use it on schedule. Anyway, this new product comes in a bag as a soil amendment. Suppose to offer the same benefits as the tea. I'll check root development this weekend to see if any difference in the plants using this product.