havent seen your nick here before, you must be new. If so then welcome to ff
Umm, bonnet scoop might serve its purpose because the engine bay is so enclosed and allows so much heatsoak into everything, any fresh air would be good.
I have modified my grill slightly, have a cold air intake and retained the standard intake aswell. i will have pics showing this soon.
I have realised some improvement in drivability aswell as much lower engine bay and engine temps.
I wouldnt install a scoop, unless the car was already done up alot,
I like my bonnet how it is

connecting a scoop upto the airbox would be a MISSION if you wanted it to look good but if you did it properly would be a very good way of improving performance.
for cost effective solution buy a panel filter from
www.autospeed.com and then get some flexible 2.5 inch plastic pipe and make up a cold air intake. stealth and slightly added performance = good