Doors and Windows - solar room addition

I live in a nine year old house, that still has french doors in the air to the house, where the sun room goes. We can not agree on whether to make it ground level with the cement type floor or even with the house and stairs on the outside. Would I have to have a special foundation support to keep a cement slab from cracking up? Would that be too hard to have poured, or is it best to do the foundation thing with it raised. Won't it sink and pull away from the house either way. We have a high water table, living in the flat farm lands of the midwest. I would hate to spend the money on something that will be a gappy sinking mess later. I have purchased 4 6' X 8' tripple pained vapor barriered windows that are mirrored and and bullet proof on the outside. Think of me on a riding mower instead of bullets flying :)They are heavy and I want a full on roof. Not one of those light weight prefab jobbers, that is my worry, too heavy and what foudation do you think would keep it level longest?

I would have it built with the floor at the same level as the house floor. If the stem walls of it's foundation are properly tied to the foundation of the house, there is no possibility of it pulling away.

thank you for your input!