IME you will need to jet for about "80 bhp" to get 100bhp@crank on most engines if you get the mixture right and are running a decent bottle pressure (900 psi or so i find works well personally)

Holley controller should work ok, although depends on what model it is and i cant profess to be an expert on them, but i dont think it will allow you the "nitrous delay" option that ideally you want to be using to stop yours going lean.

As a cheap fix you could make sure the nitrous-distributor pipe is longer than the fuel one, by trimming the fuel line down to the absolutely minimum length you can get away with and going straight over the plenum even if its not such a pretty layout.