Just go with the "MAX AIR" with the K&N filter. The HKS intake will not give you any power over the K&N x-treme filter that comes with the kit. The K&N actually filters better than the HKS. The gain is coming from blocking out the hot air not from the filter itself. As far as the "MAX AIR" is concerned, it will give a BPU Supra 8-10rwhp on the street vs. an open element filter and 8-10rwhp on the dyno and street vs. the stock airbox. On the dyno most people have the hood open so the air is typically not that hot. This is why you won't see a gain on the dyno for the "MAX AIR" vs an open element filter.