On the BMS intake, this thread has some data you might find surprising. And you can easily recreate the tests yourself using the JB4 logging which includes air intake temperatures:
http://www.n54tech.com/forums/showpo...70&postcount=1
On the BMS B58 OCC the kit includes the OCC and CNC machined fittings to attach it to the factory lines without having to cut anything. Just use their kit and relocate the OCC to another location if that is your prerogative. It's a relatively compact size.
Mike