Help Me Design My New Grow Room!

Hello everyone! Just moved into my new apartment and I am stoked to start my next grow. There is a perfect little storage closet that I will be using.

It measures 5' W x 5' L x 7.5' H. What is an efficient amount of lighting you guys think I should use? I would rather not have to ventilate and will probably be using a combination of CFL's, LED's, and a T5. If I were to use HPS, any advice on what I should use and what type of ventilation I would require? Thanks! I will be growing using RDWC hydroponics

There is 187.5 ft^3. How often should that amount of air be exchanged per minute?

In that space just use a single 400W or 600W HPS for flowering. You might be ok with just a couple of fans. The plants not only can take a little but of heat but actually prefer it. Just keep it at or below 90* F.