I ran nitrous a few times last year to race at a local event. It basically was a band aid for my engine that desperately needed rings and I didn't have time to replace them. I use a gen7 dfi ecu for engine management. You can pick them up for less than $1000 now. It has an awesome nitrous controller. Its actually 3 stages. It will add the fuel based on what info you input.
It asks what the orifice size is, bottle pressure, etc... It has out puts that will turn on the solenoid. So, basically all you need is a nitrous feed and no fuel. I even helped a friend get his car to work on one of these setups too. We had instant success.
If you go that route, I can help. Just think...no more chips, no wot switches, no fuel solenoid, just load in whatever tune to turn off or on, no guess work on how much fuel....BC the ecu formulates all that. Plus the gen7 Nos controller has safety features....it will turn off the Nos based on what limits you enter such as a rpm high and low, wideband a/f limit, voltage, timers, etc... On the timer subject, that's another cool feature. You can have it come on a certain time after you leave the line just in case traction is an issue.
That's my .02.
