2112, the 2006 if you want the 5cyl would be the best case scenario. My suggestion is to stay away from the 2007 and early, pre-January 2008 manufactured 2008 chassis. Our first Sprinter was a 11-2007 manufacture date, and over the course of 2008 &'09, we had several software and the short turbo hose issue crop up that were factory installed on those made after 1-2008.
Some friends of ours recently bought a beautiful 2005 Sprinter class B van that only had 22k miles on it. Virtually looked like new. He took it to the local Freightliner Sprinter dealer, had them do a once over of all filters, fluids and do a tune up. Cost him about $1k, but then he knew what he had, and he's got a gem. The twist on the story is it took him about 18 months of looking to find it. Ended up having to go 600 miles to pick it up....may be what you have to do