Maybe I'm wrong, but it looks like a wet kit. If he starts with a lot of fuel and a bit of nitrous and goes from there, it should be possible to get it tuned without wrecking anything.
The bottom ends on these bikes are already very strong. Rods might be a problem at 100hp, though. I guess you don't have to do much more than throw a rod to start punching crap through the side of the motor...
Incidentally, nitrous oxide isn't oxygen mixed with liquid nitrogen, and they don't use it because O2 alone made too much heat. If you pump pure O2 into the cylinder, you get severe detonation, because it's so reactive. O2 would cool the charge as it goes from liquid to gas, same as N2O, but it makes it harder to control the timing of the ignition.
Nitrous oxide is its own compound, compressed to about 950psi, which keeps it liquid. When it's released through the nozzle, it undergoes a phase transition that cools the charge. When the combustion starts, the N2O breaks down into N2 and O2 (2 N2O molecules make 2 N2 and 1 O2 molecules). The N2 is inert, the newly-released O2 is available to burn that extra fuel and generate more power.