Locked Up Manual Transaxle

On Christmas Eve!!!!!!!! I was driving my 97 cav and pulled out of a parking lot, shifted to second and the car seemed to shutter, I was concerned but put it off as driver error with the clutch or something, but probably 100 feet later i heard something pop, break, or snap... Then a hissing sound like a popped fluid hose, or vacuum line... I immediately shoved in the clutch and took this shifter out of gear (or so i thought) I new it wasn't good so i tried getting off the road ,but almost immediately the front wheels locked up and I slid about 5-6 feet. This all happened in a matter of 1-2 seconds from the shutter to stopped.
Once we got it towed back to our shop we started looking it over and have eliminated any shift lever, shift box, fluid, and cv joint problems. When you spin one front wheel the other spins oppositely. We are now thinking a gear is busted and wedged, it's locked in two gears at once, broken shifter arm pin........
And to boot it was just in the shop a few days ago because it wouldn't start (=new starter), and oil change. This is definitely not my favorite Christmas,LOL.
Any help would be greatly appreciated.
Thanks, harris.

Ouch! Sorry to hear, man!

we've decided to have a local shop remove the transaxle and we will look at it. Since we have a good knowledge of hi-perfo manual trannies from drag racing (i.e. Liberty, Lenco, Richmond...) we will tear apart and look for ourselves. If anyone has any expertice in this area it would be greatly appreciated.
Thanks, harris