What I would do is measure the physical size of the fixtures and add 4 - 12 inches per side; that's approximately the good grow area for flower for most any LED fixture...and yes, the manufacturers outright lie about coverage. LED grows well only what is directly under the fixture and a few inches to each side about 2 - 6 hence adding 4 - 12 inches to the size of length and width of the fixture to determine the flowering area for that fixture. As I understand, the apollo 8 is about 20 x 11 inches in size so if we fit it in long ways on a 2 foot tent we would have excellent coverage for about 15 - 19 inches...so that would easily translate to your 2 x 4 tent. You don't provide any size info on the 270 watt panel but the three apollo 8s will cover a 2 x 4 very adequately. You could actually grow well over a 2 X 4 tent with two of those panels on a light mover; you have enough wattage. You could consider this if efficiency/ grams per watt is important to you or if heat is an issue.
Now the issue, I think for you is getting the right spectrum. It looks like you have primarily red/blue leds there so some white to round out the spectrum would be nice - fluorescent side lighting would work great and be relatively cheap. The additional heat may not be much of a burden since you are looking at CO2 and plants love to be on the warm side with CO2.
As to your soil - I would take a look at subcool's area in the organic section...or true living organics by the rev..or something similar. My first grow was with ffof and ff nutes. It will work but over time, I learned better. Take it to heart that the secret to a good soil is the QUALITY of the compost. You either need to make it yourself or it will hurt a little to pay for it...but then if you do it right, you don't need a lot of expensive liquid nutrients. You'll need to do some reading but it will be worth it if you love tasty, smelly bud...at least something to think about for the future.