Possible suppliers
The two biggest companies for camshafts I know are www.kentcams.co.uk & www.pipercams.co.uk (in the UK). They can probably make a cam to your specification aswell.
I remember Schrick cams from a few years ago. I believe they specialised in VW/German cars. Had no experience of them.
If you do get a new cam I would be interested in the results with your variable timing...!
Happy hunting