I don't think you really "size" them since they are all small and let out a little bit of air. More like you need to select them based on pressure, temperature, and system fluid. Call TACO and ask them what they recommend for your application.
If you have already identified the need for AAV and not another solution, then it should be selected to match the pipe size it is connected to. So contact manufacturers first.
Where you can make some savings is if you can reduce the quantity of those AAV...