Heres some pics of my set up.
Bars are down hill mountain bike 2" rise, 1 1/4" clamp diameter and 1/8" wall thickness (so they are plenty strong!)
Clamps and turn plate I fabricated myself, Water cut from Aluminmum plate and Anodized.
They are so adjustable and feel so comfortable (comming from a Dirt bike background) I never felt ski bars felt right. I had to machine up some 3/8" long spacers that fit under the chin pad to raise it slightly at the back so the bars don't clash with the chin pad when turned.
Total cost US$80
I have been using them for about 8 months and havn't looked back!
Cheers
Tim