obviously a roll over can be extremely dangerous, but has anyone rolled without a cage? what happened? will the stock body take a roll over without collapsing? where can i get a roll cage?

It depends on the speed and if you want things to still be square after.

Tracker rolling at 30:



Tin Top Sammy tipping on it's side on a hill:


As for the roll cage, is this for a Sidekick or a Samurai?  I use a Davesport cage in my Samurai and a home built cage in Project Trouble, both have held up fine to being thrown on their sides.  Admittedly we tested the Tracker one at a bit higher speeds.

Petroworks makes a bolt in sports cage for the Sidekicks you can read about at http://www.zukiworld.com/month_120108/feature_gear-guide-petroworks-sidekick-roll-cage.htm

I (we) rolled Drone637's new race car during a FIELD TRIAL, the body just got down to the roll cage.  It took a tractor almost lifting it off the ground to get roof back to almost right.


So with that and my nephews rolling his Tracker up on the top, Yes you could roll one without the roof collapsing.  Hitting a tree (or other obstacle) while rolling may cause more damage.
We built the Trouble Race car roll cage with about 60 feet of 1 1/2 DOM.  Took a couple days to fit it up, another day of welding, and then painting it.  First roll cage I have bent, and wasn't hard to do.  A friend lent us the tubing bender, otherwise we were looking at $350+ for a cage.  If you start looking in your area, I am sure you will find a couple of shops to build you one.  Low Range has a 2 door cage starting around $400.