what size for ultimate handerling?

[Humble]

Sounds like it'll come down to cost and you should probably do a little more research before deciding. Lightweight large diameter wheels and sticky tires will probably cost as much or more than regearing your tranny. I speak from experience on this.

The reason other guys are running big wheels is because they need big brakes to stop heavy cars without fading. Not the case with beetles where you can get away with small disks. Most of the rally teams I know of (on this side of the pond anyway) are running 15" and 16" even on tarmac unless you're talking wrc but even then I think they top out at 17".