I had the same as Ryan but without a decat and OBX mani, I made 0.1bhp less My advice is have a go in a fte, that will definitely make your mind up on whether you wanna spend more on the NA engine or just save for a turbo!
I've only ever seen A'Pexi N1 and 5zigen exhaust having an angle, dunno about HKS, Blitz, J Performance etc I got mine custom made on the NA, they used one of those exhaust holder stand thingy's to support the box and weld custom hangars into place