Same routing and diameter as the stock system- muffler slip-fits to the cat, uses the same rubber grommet on the hanger over the rear axle, and it had a funny clamp with a rod welded to it to connect to the stock hanger at the rear (which I've since trashed and made my own hanger). Worth noting that the stainless tip kicks over to the passenger side, which means it can interfere with lift shackles/springs.
The cheaper kit is probably the way to go if you don't have a late 00/01, or don't care about the fancy tip. The cheaper kit appears to be 2.5" (the kit I have is 2.25"), and should still be pretty much a bolt on.