At that power level, I would certainly be looking at port injection as sabat suggested. Spraying the airbox is very non-precision, and mixture from cyl to cyl can very quite a bit with a single fogger. Any time I do a nitrous system on anything, I suggest a wideband O2 sensor and display. With a dry shot and power commander, it's easy to stay on the N/A tune and hit the spray, or on a wet system to have a fuel pressure or flow issue. Keeping an eye on the mixture helps you catch those issues before they get expensive. Also, running an RPM window switch is not a bad idea. It's easy to wind a bike out a bit in a standing mile, and if you run your RPMs up past the top of your fuel map in the power commander, the nitrous will keep spraying any you will go VERY lean.
As for plugs, the NGK CR10EK is a dual-ground plug that has less of a tendency to develop hotspots at the electrode tips, which can cause preignition. Though that's not such a big deal running race gas, it's still something to concider. They are a couple bucks more, but there's only 4 of them, eh?
