You can use 1/2" OR 3/4" electrical conduit (EMT) to fabricate a long pipe. I like to use the kit supplied exhaust pipe and flange, cut it from the muffler then use the EMT and fabricate a new pipe back to where I want the muffler to be. I use TIG but a wire feed, MIG, welder will also suffice. Conduit benders are cheap and available everywhere, Ace Hardware, Home Depot, etc. It takes a little practice to learn how and where to bend but after you get the hang of it you can fabricate a custom exhaust that will look good and function well.
Tom