I've seen HKS FMIC, same size as side HKS, I've seen FMIC's that you have to take off the front bumper to get them to fit on the car ( safety hazzard ), side upgrades are good for 900hp, so I see no point but looks for the FMIC. That and pressure drop the bigger you go. But if that's the price of that kit, really can't go wrong there, I'd do that price. What's the pressure drop on the unit and are the vents running side to side or up and down?