Check out Spax for their raceline series. They came recommended to me by a gentleman who races in the Kafer Cup series...
These are excerpts from two e-mails between he and I.
"For SPAX racing suspension you can look here:
http://www.spax.co.uk/SPAX-competition-page.html
To use them in a beetle you have to remove the torsion bars and replace them
by a axle with ball bearings (hard to explain - especially in english)."
"I only used SPAX G616 for the front - for the rear I used Bilstein shocks
and Porsche 944 turbo torsions bars (more due to evolution than any other
reason).
Clearance is not a problem - lots of space left...
The 1st and 2nd place of the German Boxerpokal 2004 (
www.boxerpokal.de) went
to 1200, not 1303 Beetles :-)
But it's easier to adjust the front suspension of a 1303 - takes quite some
time to find a good setup for the 1200 front shocks."
Good luck