Ventilated front discs

[Pablo]

This is a spacer kit that I found a while ago, for a triumph iirc but it shows what you need. In the end I went for the CSP kit.

[evilC]

Its all a bit of hard work making spacers up and then getting all that to work with ventilated discs that probably weren't intended for the application. You would only go with the spacers if the change to ventilated discs was easy as in the early/late conversion on the Range Rover Classic. If you wanted to go with vented discs I would think that it would be just as easy and cheap to select a vented disc caliper from the vast range now available that could have some corrolation with the disc selection.
Without pouring through the massive collection of discs the second option would be to machine some bells and then add competition discs and calipers such as AP, Willwood, Brembo whatever.. The wallet needs to be a little fatter but the whole reason behind the competition brake scenario was to be able to customise the brakes relatively easily.