Mazda Forum - Mazda Enthusiast Forums

You can do a Google/Yahoo and buy it online. Or any parts store, or exhaust shop should be able to help you with that too. It usually comes in 4, 5, 8 or 10' lengths.

How would you bend it to the correct shape? You need a proper tubing bender for that or it will end up with a ton of kinks, which isn't so good.
Here's another option for you though: http://www.jegs.com/p/Flowmaster/Flo...60020/10002/-1

Honestly though, you might just be better off just taking the car to a muffler/exhaust shop and tell them what you want. They have all the proper tools, equipment and hardware, and if they screw it up, they have to fix it.