fasteddie...I'd put a Y after the pump and use another regulator. One blue pump should be able to feed both systems easily.

The only issue I've heard of using a small pump like a Holley Blue deadheaded for the nitrous side is that when the solenoids open, the pump can't recover from the pressure drop as quickly as a big pump can and you can have a lean condition at the hit. Now, having said that, I know a lot of folks who have run setups like yours for years and never had an issue. I ran one too for a while, one dedicated holley blue to feed just a 150 shot, and never had any trouble w/ it.
It'd be ideal to have a return system so the fuel isn't sitting there banging against the solenoid until it opens.