You used to be able to buy a new front lower shock bolt at the parts store. I think it was a Monroe part number. I'm guessing they aren't available anymore. I can measure one for you when I get home. Did you have to cut yours to get the shocks out?
The nut is completely stripped, I went to 3 different stores with no luck. It looks to be ~M14 and the biggest they had was M12. My buddy has been rebuilding the suspension on his GTO and the rear shock bolt is the same size so he gave me his old one. Some of the threads are damaged and it won't tighten all the way so I still need a new nut at least.