Nismo R-tune cold air intake, will it work well with Gibson cat back exhaust?

Yes it would.
Any intake and any exhaust will work together.

If u havn't purchased the Nismo Cold air intake then don't do it cause U will save a lot of money if u just got the regular K&N Intake. The Nismo one is the same as the K&n regular one, but it has Nismo decals on it and stuff for advertisement, But it is still a good cold air intake either way, Yes they will work together. Good luck and hope it works out for u?