if its a race-only car, victor all the way. For the 180's you won't need more than the standard vic jr.
If you still require some drivability, the rpm air-gap is a good dual plane manifold that will keep your lower end torque up.
Really, the manifold, heads, cam, compression, and converter all need to be matched to your application.
However, I'm assuming, since you are looking at a big shot (250-500 right, been a while since i've been in the nitrous game), it's probably a full race set-up, so again... vic. jr.