Pistons
If you want to help the top side of the piston to withstand more heat, a hard coat anodizing process will do that. Some top fuel pistons are treated that way. This can be done at an anodizing plant other than at the piston company as they send it out anyway to a specialty company. Hard coat anodizing is better than just a heat coating sprayed on top, I believe. It will go about .002" into the piston and add about .002" on top.
Then a skirt lubricant coating can be added to the sides to help with scuffing from the extra pressure of nitrous. Most piston companies or specialty coating company will offer this. Be prepared for delays as the piston company sends them out and they are not in control of the coating company scheduling.
I have been thru this with JE and others and it always takes longer then they say.