JJ's CTD

Hey guys, I need some help with a muffler install. I picked up my new Nelson 86127 40" muffler today. That thing is big, four inch just doesn't sound big, until you can put most of your arm in the muffler. Both ends of the muffler are cut back about 1.25" in 6 places, to help with clamping. What type of clamp should I get? I think a regular u-clamp isn't going to work, not wide enough to cover the slots. I've seen different types of band clamps at NAPA, but I would like some help. Also where can I pick up about 6' of 4" pipe? NAPA only sells it in 10' stick @ $70. Summit also sell 4" x 4' stick, but I would like a 6' piece if I can find it. Oh yea, I do have a 3.5" to 4" adapter.

Thanks for any input.
JJ