So what I'm looking for is a custom exhaust that will connect to my AD-E ST kit and run all the way back, fully divorced with each side going into a Y pipe splitting off into two pipes. One pipe is straight through, with an electronic cutout. The other pipe goes to a bullet style or any muffler which fits the given space, and then merges back into the straight through pipe and returns to a single exit. Same thing on both sides. Basically this but merging back into a single pipe: