wow hold on there billy!!

before you get carried away ( and belive me i know on these cars) let me explain the cooling system on the bis.... its crap! well not exactlly it should be perfectly addiquate, but its flawed in some places, but the good news is that it can be fixed.
firstly fitting a cold air feed on the side using the existing vents wont do much as the air rushing by wont be sufficiant to chill the rad, and the rad fan sucks air from the drivers side, over the engine, and out of the passenger side so you dont wanna block it up!. what i'm doing on my bis is fitting a pacet competion fan. It will suck twice as much air, and i'm also wiring it in to a switch in the dash board too, and if you have the money, invest in a "thermostat transfer kit". this moves the thermostat to the top of the engine where it should be.
i love your enthusiasum for the bis model as it does come under fire alot for poor reliability and it does'nt get the tuning support of the air cooled, but if you sort the cooling out they are a very good little engine.