You have already said this is a build for a street car. Why are you so fixated on this 550 HP # when you're never going to know if the engine makes that much power or not? Build the engine to suit the application and it will be more enjoyable to drive the car, regardless of the peak HP it makes.

Re a stroker vs a standard 440... up to the limitations of the cylinder heads, camshaft and induction system, a bigger engine will make more torque earlier. The extra cubes will allow for a somewhat larger cam to be used and maintain the same general characteristics for idle, etc. The bigger engine won't need to be revved as high to make the same power, nor will it want to be revved higher if the induction system is a restriction in the first place.

I don't know how much other information you've posted on the car itself (gearing, transmission type, etc.), but it all factors into the engine build parameters.