I would stick with a kit. Check out
www.speedshop.org , they have barebones kits (just nozzle lines, fogger nozzle and solenoids) for $200. Then add a bottle on top of that, and the main line that goes from the bottle to the solenoid, bottle holder, pressure guage.......
Just get a kit, try to find a used one. Pick up a NOS or NX wet kit and upgrade it from there. Oh yeah, not to be a dick or anything but nos is a brand. Please don't refer to nitrous (nitrous, n2o, juice, spray....) as nos, that is like calling an exhaust a mugen.