ouch, that really sucks, do you owe someone money or something?
If you had rocks in your head (no pun intended) they most likely got in the valves, in which case you're going to need more than a new head, the pushrods are most likely bent if a rock got jammed in there, and if any made it into the cylinder then forget it, probably all scored from the rocks. If it was just a couple little rocks in the head that didn't get mixed up with anything it might not be a problem, but form what you describe (stalling, etc) you probably have severe damage. Plus depending on how big these rocks were, if it ran long enough to get oil flowing into the heads, they could have been washed down into the engine in which case it would make it even more of a total loss.
get as much money as you can from your insurance company and get another car (unless they're willing to put a new or rebuilt engine in it)
I'm reminded of the kid that poured sandblasting sand into his intake with the car running trying to do a "do-it-yourself port and polish"
http://forums.audiworld.com/a4/msgs/1567770.phtml