you can also go to 17". I have 17's on my doblo and there is plent of clearance for calipers, suspension and turning on full lock. It looks like you could even go bigger than 17 however, do this at your own risk as I haven't tried it and not seen it recommended anywhere.
Just a bit of an update, I've bought a set of four 16" alloys of a Alfa 147, they are fitted with 205/55's and they sit well, nothing catching or rubbing, I'm going to get the wheels refurbished in gun metal gray before fitting them properly
Let me know how you get on if you get your wheels aligned. I took my van to a garage last week and they did the alignment but wouldn't do the camber because they weren't the stock wheels.
The mechanic was a massive arsehole so it could just be that garage.