Where to go next? Low 11's high 10's??

Bang for the buck, I would take off your Edelbrocks and get them fully ported. That plus more cam should get you close to what you want (would be better if you can afford an 8" converter too).

As far as nitrous goes, I ran a cheater kit for about 8 years when I lived in Colorado because the air is thin up there (over 9000' DA in the summer)...if you have your atmosphere in a bottle it helps a LOT. That motor I built specifically for nitrous use. Nitrous has is a low initial cost, but it gets expensive quickly over time if you use it a lot (bottle refills are NOT cheap, neither is race gas). I took my system off the car when I stroked my 360...no real need for it at that point. If you have specific N2O questions shoot me a PM, I'll try to help.