Looked around and it seems hard to find somewhere to buy this system. anyone help me out?

When in doubt, Motowheels

http://www.motowheels.com/italian/myproducts.cfm?parentcategoryid=660%7CDucati%20Exhaust&productID=4540&showDetail=1&categoryID=671|Monster%20Exhaust&vendoridtodisplay=60%7CQuat%2DD&filterFor=&collection=168%7CEuropean%20Motorcycle%20Parts

I also saw a bike or two at Speeds kitted up with them.  So if you're from Bal'mer hon, they are close by.

motowheels...  nuff said

"Underbike full exhaust system for the Ducati Monster S4R <'06. Includes exhaust canister but will require your stock header pipes."

If you look at the pic in the link, it doesn't look like those are stock header pipes to me.
Am I wrong?

Curious because I took off my bladder/udder thing and ran straight from the header to the exhaust pipe. But I've been looking a this exhaust and was wondering if I'd have to put the udder back on.

you use a part of your old header if you have a bike other than the samller monster 6xx. it begins at the engine and ends where your oil filter is.