Any of the top piston manufacturers can make custom pistons for you. I just had a set made by Ross that came out exactly as ordered. I opted for the skirt coatings, but skipped the top of the piston coatings as mine is N/A and no No2. It might be something you are interested in looking at for you application though.
Those initial shock loads will sure find the weak point in your suspension. Are you running a manual trans?
Carbon Fiber drive shafts can cushion shock loads from what I've read, but if you crushed your rear axle tubes on launch, you may have to swap that rear end out too.
What type of traction system do you use on the rear of the car?
