The HPI Nubz work on a standard buggy - they bold right on to the 17mm hexes and clear the suspension arms for steering
I have a photo of it here
The Nubz are great, just don't use them on asphalt.. they'll wear real quick...
I use them on my Ofna Blazer and they rock!
They are a great wheel/tires combo for general buggy bashing and you don't need to do any radical spur/pinion re-gearing either.