Due to emmisions laws, I need to have one cat for me to pass. Anybody ever done this, or seen it done?

 

To have long tubes and a single cat would require the pipe coming from the drivers side collector to make some impossible twists and turns to mate with the single cat on the pass. side.
FLPs have the pass. side cat almost in the stock location of the stock single cat. If in your state, like they do in OH, they just stick a mirror under the car to check for a cat, FLPs would work. FLPs also have the AIR and EGR hookups. That's also provided they don't look under the hood.