Well for starters there is no continuous frame under the car. That's why it's called a uni-body car. You have a front sub frame and rear frame rails. They bolt to the body but do not connect. If you're going to take on a massive project like this you'd better get a handle on exactly what it is and the correct terminology or some body else will be buying your tore apart car from you for pennies. And yes the body will buckle if you don't do it right. Good Luck.
Oh, and welcome to the board.