Purchase of a vehicle Family combi

Hello, I’m looking for a used 2nd car for a few weeks. We are just in the middle of the house purchase and move to the country of the future work path is 28 km easy, add shopping trips with 20-30 KM every 4 weeks we visit the parents 200 easy. We are a 4 head family 2 children 1.5 years and 3.5 years. We have a budget of 250€ for the purchase of a vehicle I have to date after (year of construction 2001-2008)Ford Mobeo Kombi, Renault Laguna a Kombi and VW Passat Kombi looked at, but I am open to any hint, tip, criticism. The problems I had when looking for or calling the dealers so far were: that they only sell the vehicles to dealers, the vehicles are only for export, which they were not wide to supply the vehicle with Tüv. Environmental zone is rather marginal. Now to my questions. 1. prefer a diesel or gasoline? 2. Which vehicle with which engine service can you recommend? 3. from Which Bauj 4. How many kilometers should the vehicles max. have that we can still get there about 4 years? I am also open to offer/advertising suggestions. Should questions on your part be open to the Kaufrofil I will gladly answer them. I look forward to your suggestions Daniel