Thinking about going LED and got a couple of questions.

Hey guys. I've been using my 600w HPS light now for 3 years. Had a great little harvest every time. I've been using the SCROG method on 4 plants in soil and a 4'x4' area. I averaged out 450grams at every harvest. Have the carbon filter, fans, inlet, basically everything for a basic set up.
But this summer the temperatures outside reach 35 degrees Celsius, so you can imagine how hot it gets inside with the 600w light. I can now see the stress on my plants from all the heat and im starting to worry.
Anyway, down to the point! I want to go LED. I heard from some people its crap, others say its great. made up my choice, im going for it!
But what i don't know is, do i use one light of a high wattage close to the HPS light that i havefor all 4 plants? Or do i get 4 smaller LED lights and place one over each plant? As you know each plant takes an area of 2'x2'. I dont want my harvest to suffer. If anything i want it to get better.
Does anyone out there have any suggestions?

i can only average about 56 grammes (Dried) per plant!
how do you do it.
am i doing something wrong.
600w hps dual spectrum, canna professional soil, feeding ph at 6.5, growth technology nutrients veg, then flower and boost, 28c temps, veg for 3 weeks from seed 18/24, flower for 55-65 days 12/12.

In my last grow i had 4 Pineapple Chunk grown from seed in 4 25gallon smart pots. For soil i used 1 part Perlite, 1 part sand and 2 parts regular potting soil. For nutrients i use Biobizz but half of what it says on the table and only every other watering. The water was at 6.2ph, but i dont think that matters. The only thing that i do so i can get more is my veg cycle. I grow it longer. Because i scrog, i let it fill out the whole 4'x4' area. depending on the strain that i have and the temperature at that time of the year, ill let it veg from 8 to 10 weeks. Then it flowers 8 to 10 weeks. the whole cycle takes somewhere from 16 to 20 weeks. Thats why i get more.
But there is so many other ways to get more... it just takes experience.
I use to grow 9 5gallon pots in the same area for less time and got roughly the same results as 4 plants do now. And sometimes less and the buds were not as good as i grow them now. But i know i can do better if i get a better set-up.

When you flower with an LED, you can get them pretty much right up against the light...Way closer than an HPS....Therefore the spread isn't as far. If you are running 4 plants, I would get 2 stronger ones. 1 big wont be enough and 4 small ones won't get the penetration you're looking for especially since you veg for 8-10 weeks like I do.

edit:

I put 2 under each of my 240W Blackstars and 2 under my 600W(which is in between them) and just let the light spill over to help out the 240s.

I would get 2 600w Blackstar LEDs for your space, Or you can buy 4-6 135w Blackstar UFO's. Can't go wrong either way, both will grow nicely.

On second thought, I would do the 6 135w Blackstar UFOs for your space. You can spread the light out more with 6 UFOs as opposed to 2 Panels. The UFOs have 3w LEDs as well, the 600w Panels only have 2w LEDs. You can probably get a deal on 6 of them, for like 150 each.

i use two 600w blackstars in 4x4 area and have had wonderful success, even with the 2w chips, excellent penetration, girls love em and I love my nightstick size nugs! they still produce a good bit of heat but nothing compared to one 600w hps, its like night and day and they use less power, Im one of the "impressed" users of LED, give them a shot! 600w Led keep even the nugs at the base of one of my untopped girls growing strong and with a mylar wrap in the grow area it helps squeeze every ounce of goodness out of the lights

One more note, all of my girls are extremely thick, they were vegged longer than normal (almost 3 months) because of odor issues, before a CF was acquired, so even with very thick plants lower fan leaves still get plenty of light, with LED's the most important thing to ask your supplier about is the amount of chips in the lights and also ask them the lights PAR, the cut the bullshit question, google a 1000w hps PAR and compare to get the most powerful light for your money