Some?!... I wish! They are popular! Sold mine on eBay this week. Keep an eye out on eBay. They normally pop up for around £200 (full system), and will probably cost another £50 to ship and £40 in taxes/fees. Just remember to get the link pipe too (if you get a full system it will have this and the headers, but your headers are the same), because your link pipe won't reach. Obviously lower fairing panels too.
Sorry, messing around. However I did have to dissapoint a few people who all made genuine offers. I'll dig out the supplier of mine, because it might be worth messaging them to ask if they have any.
I'm sure I seen a dealer with the belly pipe fitted on a new bike. Should to speak to them to see how it's done and order what you need.
Go up this thread. The picture is what you need. More information here: http://ducatiforum.co.uk/threads/euro-4-exhaust-swap.43125/ That auction has the under belly muffler/silencer and the y-connecting piece. They will fit straight onto your header pipes. In addition, you would need the fairing panels, and if you want to keep the flapper valve working you will need the 1299 servo (because it pulls down through the center of the belly instead of around the side), but you would be better just leaving the flapper actuation off and removing the error.
Out interest for some that may be interested, does the 1299 Akra belly pipe fit the link pipe? (in case someone is loaded)
If the 1299 underbelly fits onto the 1299 link pipe (with flapper valve) then you would still have exactly the same problem. It would be interesting to know if the Akra belly for the 1299 and 959 are the same... if they are, then they would have to change the link pipe on one of them, and as the 1299 was around first, they would probably stick with that. Also, if they fit the 1299 straight after the flapper, do they introduce a flapper to the link pipe on the 959? (I.e. Fit the 1299 link pipe). I haven't seen the Akra, so can't comment.
Judging by this photo, the 1299 akra goes straight onto the 1299 connecting piece, so you would still need the connecting piece.