Well, you could try for a stock one from Bug City, either new or used:
https://www.bugcity.com/shop/s...asso?pquery=sway+bar
Or maybe try SoCal Autoparts for a stock one and a lot less money.
https://socalautoparts.com/sho...stock-reconditioned/
IIRC, the Stock bar diameter was 1/2" or less, depending on year, so that should be just fine - Also IIRC, Vintage Speedsters used to install stock VW bars on their cars - the car is lowered a bit so the bar got installed upside down for clearance with the bumper mounts.