conversion to disc-brake

Hi for all !!
have a question; is there a conversion-kit on the market to put disc-brakes on a 8 " inch front wheel of a VNB?
and what do i need?

take a look at this page:

Worb5 - Discbrakes

or just check out

I think heĀ“ll also be able to do the same with vna/vnb forks.