You are asking too much...LOL no J/K
I'll do my best for ya. haha
So 5X5 huh, well heres what I would get with that space...
Probally a 1000 watt HID HPS light...
cheapest price on the internet for a good 1000 with everything (reflector, ballast housing, all power cords) would be from HTG supply... $200.00 even
If you have the money get two 1000 watts, but only do that if you have the money for Heat extraction... Also HTG supply can supply you with a can fan and GOBLIN charcoal filter for $209.00 that you could use for both heat exaction and odor control
Then you are gonna have to decide what "system" you want for your plants roots..
Cheapeast set up IMO, is COCO and Grow bags....
you can cut this to improve drainage (good to do for begineers) with Perlite or Hydroton.... (Perlite is cheaper) reccomend the hydrofarm kind...
COCO is also re-usable..
But if you want to go with DWC/bubblers or anything feel free too.
Also if you need info on DWC/bubblers feel free to PM me...
IMO if you do go with bubbs/dwc, dont use bid tubs, use 5 gallon buckets at 1 per plant, and rig it up with a gravity system (again PM me and I will help)
Also are you walls already painted white by any chance, if not you will need mylar...
or paint (FLAT WHITE is the most reflective color of all)
Nutrients, can I reccomend a great begineer nute?
SUPERNATURAL Aqua or Terra powders. I LOVE THEM, also they come as powder solids and you get alot more out of it than Liquid Nutes... Like 3 times as much for a 1/3 the price....
So really it comes down to what are you wanting to spend, how many plants do you want to grow, and what type of system are you gonna go with?
Feel free to PM me, if you need