I ran nitrous on my 700cc mountain sled. I loved it, and it was pretty easy power. I have thought about it on my bikes as well, but did not do it after considering the following:
1. Nitrous has to be used at WOT for any real advantage. Using it below full throttle is simply wasting it since you are not developing full natural power yet anyway. On a sled this worked, on my bikes, not as practical. It is much more challenging to use except in holeshot street applications, or if you just really want to go fast!
2. If you are at WOT on most motorcycles, you are already going really, really freaking fast (at least on my bikes)
3. You have to have a ready supply of nitrous, since once you start using it, you will never stop.
With all this in mind, you can see why people favor turbos over nitrous on a bike--you will have more power useable to you, although not necessarily more power.
But, if you really want to do nitrous, Boss industries makes a setup that will work with an older carbed system (Harleys for example) in which you do not have to alter timing at gas introduction. You will run a pony bottle of high octane (race or Av gas) in addition to your nitrous bottle, and it will inject wet with the nitrous. Search information on Boss Noss. I ran a 30 HP Boss system on my EFI sled on 91 octane, and I loved it.
As far as realiablity goes, if you set it up right, and don't abuse it, it will work fine. A piston with a taller top land before the first ring will help inmmensly. So will a water cooled bike, rather than air cooled. Exhaust temperature is the real killer with nitrous, as your exhaust temps go through the roof. an EGT probe would be very helpful. I could run about a max 10 second run with my 30 shot before temps started to really get high. You will eventually notice erosion on the edges of the piston top from heat if you use it much (you will).
But like any performance idea, it will work well if you set it up right, and will be more work and tuning on your bike to keep it running right. Performance and extra work go hand in hand. If you like all of that, and this is the way you wnt it, I say go for it, and show us what you did!