I would get a petrol to be honest. Far more reliable in the long run (higher ks and out of warranty situation), none of the carbon issues associated with modern diesels (PCV/EGR), cheaper to service and they get great fuel economy from them these days. No way would I complicate a $10k purchase with a diesel.
I'd also avoid anything VW if you are shopping second-hand and out of warranty. Ask the VACC and tow truck drivers about how reliable they are (literally any other make is more reliable). I wouldn't go near one, mind you there are plenty of people trying to sell them and you can probably get a great deal.:p

