Probably in this case, starting with a tiny nozzle would be the best bet. DO3 is probably the way to start.
If you're talking about the direct port setup that is tapped in the intake runners -
I think that six 3gph nozzles would be way too much. Only the super bored out and blown big blocks are running over 15gph total.
Also, there are a number of potential issues when you move to running a lot of very small nozzles.
Everything from possible clogging, to inconsistencies between nozzles, to just being able to control the flow rates on nozzles that small in general.
The available nozzles usually come in 1gph increments, but when you have six nozzles, you are working in 6gph increments. Not very convenient.
The upside, if you did want to do the direct port would be that you could possibly cut the fuel in your tune, and run straight alcohol at a ceratain point.
I'm not sure how reliable that would be, and you would definitely need a really well built system with good failsafes, but I think it would be really cool to have an alternate high octane fuel source in the car to use on demand.
There's a company called Nelson racing engines that built a supercar (iirc it has a much higher hp/weight ratio than the bugatti veyron) that has two gas tanks.
One was the main gas tank and held pump gas. The car would run on that when cruising, and then when you start pushing the engine it switches to race gas.
I'm not sure what method they did that, but I think that idea is pretty damn cool especially for a street car.
-Riggs.