Suggestions on piston rings

Spend your money on some total seal gapless rings, it's very well spent. you'll notice a big difference in performance vs stock style rings.

I would also suggest total seal but the not the gapless top or second ring design, the N2O will cause issues. How much will the N2O be used? You want to get a good conventional plasma moly ring, cheap mly rings will flake with the N2O. Total Seal, Speed Pro and Federal Mogul all use a good process with the moly coating.

File/Gap to the instructions and make sure you get ones to fit your .040 bore, and the correct thickness ring depending on what your pistons are. The newest things in rings with N2O or Boosted motors is to gap the second ring to the same or slightly larger then the top ring to ensure gases can escape and not pop the top land and pull the crown of the pistons up. If a ring butts together it will destroy the piston.