Hydroponics set-up question

Greetings to all

First of all I am new and have not build anything (yet), however I am in the planning stages.

Here is my situation: I live in Houston Texas so I am a little worried about the heat. I have had a garden in the past in my back yard but it was on the side of my house and it was always out of site out of mind, so I wanted to bring the garden closer to me. In my back yard I have a swimming pool that is surrounded by a screened

room (like you would see in Fl )

I am planning on building the 11 plant system. But to keep my back yard

looking a little nicer I am planning on building a box that contains the unit inside, with the top of the plastic bottles being flush with the top of the container.

Some of my questions are:

What would be the best medium to have in the bottles

I plan on cutting slits into the back on the container for air flow but

wondering if it will still be too warm

Will I need to paint my plastic containers since they will be in an enclosed area with no sunlight

Anyone seen any plans on anything like this? I have seen a table top version but not an enclosed area

Should there be any problem with the over-flow pipe being under the wood top

I am planning on running the solution every 20 mins during the day and about once a hour at night - should this work, I do not want the roots drying out

My main items will be tomatoes and peppers. I know that the PH level should work for both of these together but anymore thoughts on what might also grow well with them

Thanks for any and all advice I know that this is a large amount of questions.