I drove (fleet) Sprinters for a long time, when there was just the T1N, this one is the newer NCV3, which is much different. Anyway, most of the van is similar but the engine and styling are different. Many say the T1N was much more reliable and economical. Either way, I would recommend you stay away from anything requiring DEF. I think 2008 is the last year before this mandate, but you should make sure it doesn't use DEF. The whole system is trouble and I, nor anyone I know including our fleet mechanics, would recommend that to a personal owner. Too complex and prone to trouble.
Anyway, I've toyed with the idea of buying and converting a Sprinter too and after reading the link below from start to finish I came away thinking I could swing it because I maintain my own vehicles and I'm not opposed to getting my hands dirty to save a buck. If you don't work on them yourself the short story is STAY AWAY! Unless you like to hand over your credit card and have your trips interrupted, that is. Anyway, good luck and judge for yourself. It's a good read.
Would you recommend a sprinter van - Sprinter-Forum