^ Hypergear always keeping it cool and willing to help you out.
You can't blame hypergear, you can't blame Nissan. You can't blame anyone. Your luck seems low. That option up there sounds pretty good. It really isn't hard to bolt the head back on and reassemble everything. Torque settings, set the cams, set the pistons, slap on the head, torque it up, manifolds, gaskets, studs, nuts, wiring, injectors, plenum, spark plugs, coils, turbo and your just about there!
Then again alot of guys here are blaming you for running 25psi. 25 psi will cause detonation but it isn't likely that one or two runs on this will KILL the motor.
Like I said in many other posts, if that cylinder bore is in good shape, replace that damn piston with a stockie and put it back together.