Wow, that is a perfect idea. if it were me i would knock everything out exsept the colling unit. this is already intigrated with alot of fans so you could easily switch some of those to exhaust and to intake air ( you could probably take a few carbon filters to those fans as well ) as for you SOG its an excellent idea. for that amount of space i would say 2-3 mothers on BOTTOM and clone on TOP. reason being is if any light leaks into your mothers, it wont matter casue you will be keeping them in veg stage (this creates a pro con situation, becasue if light leaks down, it will leak upwards aswell) but since you fixtures will most likely have reflectors, not much of that light will leak. as for the actual coke machine lighting up from the outside, forget it. as to solve your super stealth problem if someone wants a soda, tell them you are trying to renivate it and it dosent work. (to make this even more belivable, you could put some classic COCA-COLA or classic pepsi signs on there to make it look like an older machine that may need renivating.