Dave,
I am a NX dealer and that what kit im gonna use.....a 20922 Wet with a 15lb bottle, i am also puttin on the GenX-2 kit( heater, , fuel pressure safety switch, Nitrous Pres. Gauge, blowdown fitting and tube and dual purge) and remot bottle opener.....
you can only spray under WOT with there kits, the reason i asked about a spray window is because you can put on a Activeation Switch, its very much like a MSD with the Changable RPM chips, so all you have to do is arm the system and when it gets to the lowest rpm it sprays and then stops when you get to the higher chip.....and if you dont wanna spray just dont arm the system
they do have a stitch for WOT that works off of the TPS voltage....
or you can just save the $100 and use the mechanical switch
I am going to run a 50 in the start then jet it to 75-100 when i get the feel of running nitrous