You can reload nickel brass, but I've never been a fan of the nickel-plated cases. They are harder on dies (make sure they are CLEAN when you size them), and they will flake eventually. My suggestion would be to just buy yourself a bag of Winchester (my preferred brand) of plain brass cases. A bag of 50 will cost you around $25 ($26.99 at MidwayUSA.com, but you have to pay shipping).

Mike