If you just daily the car and dont beat the **** out of it everyday, 20's will be more than fine. You are just looking at the costs of the rims and tires at that point and wondering if you want to pay that much.
19's hands down will cost you the most money because of the price on tires is stupid high.
A set of 18's look great on these cars, fills everything out well, but its up to you one what style you want.