oh, and should i get a 75mm throttle body? C&L claims yes! some people say to use 70mm and that 75mm could be counter-productive....

Forget the spacer. The new plenum has more volume than the stock one so the same effect is already given. A 70mm will yield good gains. Anything bigger than that is not useful. 75mm will degrade the throttle response some. I have(had) a 70mm on mine before the blower install and I can say you'll be pleased with the improvement. Make sure you check the TPS voltage when you install the TB , it should be .97-.99 Volts DC. I don't remember right off the top of my head which wires you need to take the voltage from but there are people here that have that info.