IMHO the 3/4" bar is too much unless for Autocross, and the factory VW 12-13mm bar is not enough.
Years ago, before EMPI=China, EMPI made a 5/8" bar designed for the street.
A properly bushed 5/8" bar is the sweet spot. The bushings and bar size make it way stiffer than the VW free-floating design. I used black urethane bushings with grease fittings from Jeg's or Summit. I welded flat plates to the front beam, including nuts on the back side, then painted it all black.
Jim's spline design is really nice, but too costly for me. If I had a local shop that could cut splines, that's what I would have done. I used an early 911 through-body swaybar and cut off the ends. I had a local welder Tig the arms on, they are made of laser-cut 3/8" flat steel. Tig transfers less heat, I didn't want to remove the temper of the bar.
I bought the arms from a fabricator in Canada, don't remember the company name.
I used 10mm rod ends, one male and one female each side, and attached them to the lower shock studs. Works very well. I'm using the outermost of 3 holes in the arms.