Bigger doesn't always mean worse performance.  I swapped from standard 17' cast wheel to 18' forged wheel.  8kg per wheel for the forged 18's vs 17's which was ~10kg, and the car handles better, takes off better, better braking, fuel consump and overall feels more light footed.

So try to go with light and strong wheels.  The benefits are more than just cosmetics.  Best is forged alloy wheels which are much lighter and stronger than cast alloy wheels.

Here is a pic of my Volk Progressiv ME's + KW v2 coilovers drop