Overland did a nice brass model and they pop up on Ebay periodically but expect to pay around $150 when you see one.
Sunshine models also did one that I expect would be excellent but I have not seen one other than pictures. Expect to make a significant investment of around $50 which is much less than the brass models but there are skills required to build these wonderful kits.
AHM has a plastic model of these cars which obviously will be the lowest price option.
I will leave it to the more knowledgeable on the list to offer input as to which model is the most accurate for I do not know.
