grow room layout need Opinions

this will be in a shower. Dimensions are on the print. i can vent it through the outside. the ballast can be placed on outside also, to keep heat down. i have the pump, and most of the hardware ie: hoses, drip lines, rockwool, trays. have not picked up light yet. tell me if i am missing something or if wasting time or money on something. your input would be appreciated. any question let me know.

Questions?
1. the ballast i am going to buy is a digital 600watt conversion. so both hps and mh. is that to much light for a 2'6" x 2'6" area. can you have to much light. hope to expand size and # of plants later.

2.can i use with 6in rockwool in a container by itself. or do i need a rockwool slab under the cubes.

3. the t5 florescent s are expensive. what lighting do you use for clones.

4. how plants should i grow in this area.

1. That's a good amount of light.
2. I don't know Too high.
3. You can use T8's and T12's for clones, they're available at home depot, and lowes; places like that.
4. 6 big ones would be optimal.