If you are using a functional air scoop the air cleaner is best incorporated into the scoop to save space. using a traditional pie tin air cleaner would most likely be a PITA with the dual quad setup you have. An air box will have to be made to mate to the hood. K&N makes many different sizes and shape air filters to fit your application. as for speed as long as the bonding is done right 200+ MPH. Speeds higher than the car can achieve due to drag. You are talking about binding a fiber glass or ABS plastic scoop onto a metal hood right?
tunnel ram will work with a 6 pack scoop but you can not run air cleaners. I have a 5'' scoop on my R/T. mine has seen 130 mph in the 1/4 and no issues with it wanting to come off.