Not yet, but aproximately in two months we make few prototypes and test them on a typical street/strip beetle engine.
Stock case cannot be modified to wbx pattern spacing and 4" bore with success, some have done but it much work. Most of us use WBX, Autolinea or TF-1/Scat/Autocraft case. I am using TF-1 case.
I use LN engineering 4" Nickies and JE pistons, but there is also AA, JPM and autocraft iron cylinders.
http://www.lnengineering.com/whynickies.html
http://jpmotorsports.se/ms/ms/j-p-mo...-90000825-p-3/
http://www.thesamba.com/vw/classifie....php?id=117541
http://www.autocraftengines.com/components.html
Price will be no more than 1800€ / pair no matter which bore, but you have install your own valvestuff - I recommend 117mm long type 4 valves, regular highperformance seats and guides, JPM springs + retainers or CB VW650 stuff.