K20A3 Piston/ combustion chamber damage, what to do?

[dmon]

Hey guys. My car been down about a year due to me cross threading spark plug thread. Today, I finally took off the head to bring it to a shop to have it re-threaded . Come to find out the mechanic who worked on my car that found this issue fucked up (this was a year ago when it broke down). The tip of his flat head fell into the chamber, taking a chunk out of my #2 piston and damaged the head. Also it appears to have light scratches on the cylinder wall.

Is it possible to have that one damaged piston replaced (buy a used a3 piston) and have the head resurfaced with a thicker head gasket ? Is the head still usable in the condition its in??