This is far as you can come with pistons for a vw engine.
We use this JE pistons in our R&D hi-rev motors,thye are only 380g complete(94mm bore).
They are a two ring design ,domed,3d machined underside and twoway gasported.The ultimate in piston design.
 

Kolvar

Our own JE custom made vw piston wich can be used with stroke up to 86mm, 5,7" rod and still using std cylinder .
This means shorter pushrods and shorter cylstuds wich is one step up in performance.
94mm piston with rings ,pin and locks is only 420g.