I think that any A3 oil would work fine in this car.
It does not have especially high specific output, and you aren't tracking it.
The least costly oils meeting A3 according to their blenders, are Maxlife SB and Valvoline Durablend in the 10W-40 grade.
M1 15W-50 would also work well, if you can get a decent price on it.
Synthetics will not by themselves cause leaks, so I wouldn't worry too much about that.