my local exhaust shop didn't have a mandrel bender so they said the MBRP exhaust is the best choice, versus a build like yours. I wish I had a shop that could build it on the spot too.
funny you mention the noise of your aftermarket CAI, I did a test once where I removed the lower half of the stock airbox and secured the standard air filter to the top half of the stock airbox. This setup was significantly more noisey than the complete stock airbox, I didn't notice any seat-of-the-pants increase in performance.
2008 WK "S" Limited bright metallic silver exterior, light graystone interior, 5 speed W5J400 transmission, June 18/2008 build, C213RE rear differential with 3.73 axle ratio, C200FE front differential with 3.73 axle ratio, 245/60R18 Goodyear Fortera tires (stock summer tires), NV245 transfer case, GT2056V turbo, 3.0L CRD (OM642.980)