cedar, what your wanting to do is very doable. When i was a pup i got a remod on a restarant, suspended concrete floor over a basement. Anyways, after the tear out, clean up and forming up for the new pour(having never done this before), to say I was a little nervious is a understatement. The day of the pour, the engineer showed up and after looking over my work, put his hand on my sholder, smiling, said," Don't worry, the concreet isn't going to end up in the basement". WTF? This guy reads minds? He went on to say that after it set up i could take out ALL of the suports, that it would suport it's self. Well, it didn't end up in the basement and i left the center suport, but as far as i know, it is still there, used every day. Good luck with your project and post up some pics when ya can, d.