[Three Peaks]

The original parts are still available from several different sources- Cobra Restorers, Tim Gunning, and several others. I believe the Kirkham are the most easily and affordably made to original specs, since the CSX aluminum bodied car is simply a rebadged Kirkham IIRC.
The prices would be much less also. Kirkham makes a beautiful car, but they are awful proud of their parts, compared to others who can supply the same or similar parts. With a little shopping around just about any part from the originals can be found and will bolt right up to the Kirkham chassis, I believe. I could be wrong as I'm not familiar with the recent changes Kirkham has made to their chassis to accomodate their newer, updated suspension pieces.