You can say 75x75x5 until the cows come home but it still won't mean anything. It isn't what you use it is how you use it. At the moment you are trying to build a bridge without appreciating how a bridge works. More James May, less Jeremy Clarkson please.

It might be worth mentioning that all your problems are down to the idea that it will look really neat if you lift it off the floor. If you sit it down on the floor all your problems evaporate, well, so long as the floor isn't flammable