wrt the scoop size for me its more about function first - if I was going to do short twisty tracks all the time I would go for the big scoop get as much air through the intercooler as possible but longer runs and higher speeds I think I would be worried it would pull the bonnet off -
when experimenting, on closed private roads , the bonnet on mine was moving around quite a bit once into 3 figures, bonnet pins are now also in the shopping list