You'd be best to run two separate fuel systems.
I would install a small fuel cell under hood, along with a fuel pump and fuel pressure regulator.
for the nitrous system. Fill this fuel cell with 110+ octane unleaded race gas.
A carter P4594 pump and 3/8" fuel line is plenty for this.
Another Carter P4594 at the back of the car will support the engines fuel needs
run the engine on 92+ octane premimum and the nitrous on 110.
Very simple. and you will have it covered. get a fuel pressure gauge that reads in 1/4 lbs accuratly
You will find this very effective in fine tuning the nitrous system.