If you get a Zex kit, go dry. The wet kit from zex is a single fogger kit that is tapped into the air intake and sprays a nitrous and fuel mixture. A dry kit sprays only nitrous from the nozzle, and adds fuel via the injectors from an increased fuel pressure. A lot of people will say that wet is better because it adds the fuel, but this is not necessarily true for a single fogger kit. The fuel can puddle and ignite, causing an intake backfire. I've actually seen a few cars catch on fire from this.

However, since you have a GSR I would just go with the plate kit. You can run the 75 shot and be fine, and if you want to build the motor and go higher in the future you won't have to change the nitrous kit.