Here is the official response
Any 20 x 110mm DH hub will work in the QR20 forks with the use of the QR20
axle kit. You should be able to get that kit through your local bike
shop.
Take care,
Marzocchi USA tech dept.
Just received it. Must be busy
A2,
That is cdn. 300$ for the pair means around 200$ american for both front and rear.