The biggest challenge to scrambler pipes on your bike, Jake is contending with 4 pipes instead of just 2. You'll have to run both sides as McW did. But doing so, will effectively prevent you from accessing the carbs until you remove the pipes any time you need to reach them. If you do pursue this design, a great idea is to use the spring clamp flanges that Chris Redpath uses on his MotoGP pipes (ala Yoshi) for quick removal (pic below). Notice the black pieces? Then the clips on the pipes just ahead? Thats where the springs attach to the pipe, then they hook into holes on the flange. The black portion of the "tube" gets permanently installed into the exhaust port, fastened thru the flange with nuts, then you slip the pipe on and off the black tube by releasing the springs. Very fast, and very easy to service oil, lift bike form underneath, etc.
Here's a link to a place you can order exhaust components from to build your own. You could "model" it up using some Mig welding wire or other suitably small gauge wire that's stiff enough, then order your pieces, and then find a local muffler/exhaust shop to weld it up for you. It can be done by a DIY if you take some time, and plan it out.
Another option, is to get some PVC tubing in a variety of bends and Us, some straight runs, and then model it from that. Just be sure to use the proper diameter tubing to ensure you don't encounter conflicts in running the pipes. Check your steering space, where your legs will run, proximity to the gas tank, etc. pipes get hot, so be prepared for that. I'd would also strongly suggest you ceramic coat inside at least, outside too for best protection. And add a heat shield as McW did to further protect yourself from contact.
Take it and your bike to a shop to have them create it from that sample. I'd even go so far as to email Chris and ask to buy a set of his flanges and springs to facilitate the removal for servicing the bike. But a tubing bender is the easiest way, or LOTS of cutting and welding is involved. And I mean LOTS.
http://www.c5ignitions.com/exhaust-kits.html
