Lower end work while the head is off?

I have a b16a that has bad rings in the #3 cylinder. I have the head off but want to know what rings I should use for a n2o setup. Obviously, I would like to replace the pistons, rods, bearings, etc. but don't have the cash 4 that right now. Is there anyting that I should do at this point before I put the motor back together? Also, because I am running nitrous, what head gasget and head bolts should I use?