In die-cast already made some of the nicest out there are the 1:18 Lane Collectibles/Exact Detail or 1:24 Franklin Mint.
There is also a very nice smaller 1:43 by Kyosho, but it has white walls, that need to be removed and reversed to show the blackwalls.
If your looking to build a plastic model then your only choice is the 1:24 Monogram/Revell kit.
Here's what I built from the kit, but I painted the lemans stripes instead of using the kit decals.