Don't be too put off by some of the horror stories on here, after all it's what sites like this site are all about, it's where people with gripes about their cars can sound off and ask others for their experiences but, for every one member who comes on here and berates their model there are numerous other owners who have normal ownership experiences or have no problems. They just don't bother mentioning it!
If your son ever considered a Golf (snooze) or twinkly Audi (sooo boring dahlinks) and looked on any of the VW Audi forums he would also be put off by the posts on there. Hang on, I'm feeling a bit sick now thinking about that.
I would opt for a 2.2 as its the cheapest to run. Doubt he will manage much more than low 20's mpg at first until he settles down then expect high 20's, even 30 or more on a steady run. The 2.2 is pretty reliable overall, it's a GM sourced unit and it has a mechanical chain drive for cams so, no belts to worry about. Sensors will tell if it stretches and needs changing. It will be fast enough for him but, if he gets on here he will pick up lots of ideas about what he can do with it to improve it.
There is a hesitation issue with some 2.2's at below 3k rpm but, not every car seems to suffer with it or some do to varying degrees. It's known about, classed as a feature by AR and they will do nothing about it but, it can be driven round once you get used to the car or, modified out, almost.
Again, the rocking seat issue affects some pre 2008 cars but not all. Dealers will sort this if you buy one from them and it is apparent.
At least your son has taste so, be grateful for that.