How about other specs; compression, target use of the car, rear axle ratio, cam specs... Its pointless to recommend something unless we know everything about the car.
If you're really keeping it under 5500, then there is absolutely no reason for big-port heads. They'll kill low end and drivability. You can do a lot with stock iron vortecs. They exhibit tons of flow with small ports, meaning they will shine in both HP and low end drivability. They'll do really well in a 350 up to 5500 rpms without porting. With some porting and bigger valves, I've seen them lay down 600 hp in a 400. Add in the fact that they can be had for $350 a set rebuilt and I'd say they're a winner.