If you have early Beetle short axles, use 7x16s. 6s will be tucked too far in and look off.
I do not recommend the severe tucking ala GFK cars for the front if you intend to actually drive the car. That means you are better off with a 2\" beam than the 3\". The reason is that with a severe tuck, you can't steer around corners.
My car has a 3.75\" beam and if I was to do it again, I would do 2.5\". That's with 7s on the front. 6s require less beam chop.