lol, that's absolutely obvious...
I don't know what rims you have on your Wagen, but most 16" rims on VAG cars have 205/55 R16 (or 205/50, I don't remember exactly). Wheel arches are made to hold (don't know the right English term, sorry) 19" wheels, so there should be no rubbing issues on a non-lowered car.
7Jx17 and 8Jx17 wheels have 225/45 R17 tires according to Volkswagen DE and one wheel company we cooperate with.
6Jx16: ET (offset) 50
6,5Jx16: ET 42
7Jx16: ET 50
7Jx17 "Karthoum": ET 54
7,5Jx17 "Avignon": ET 54
7,5Jx17 "Goal": ET 50
Tire measures depend on each rims, but you can run on 225/45 R17 tires on 7Jx17 ET 35 as well as on 8Jx17 wheels.
I wouldn't be bothered with acceleration times. Your car is not a supersport and the difference between 16" or 18" will be in acceleration time small imo.
I personally like these rims, they're called Vision. 8Jx18 ET 50.
PS: We have a tire shop/ car service. I can ask my dad about your car.