First, check out the web sites for the for the two companies
http://www.factoryfive.com/ http://www.superformance.com/index.html.
This should give you a good idea of the quality of the components used in both cars. Then, I would suggest that you try to go to a couple of cobra get togethers to check the different manufacturers and build quality in side by side comparison.
There are some ultra nice FF and other car kits out there, but the builder's of those cars probably have as much invested in them (if not in cash, then sweat equity) as you might spend on a Superformance. Plus, those folks are craftsmen with very complete garages and tools.
Pay your money and take your choice
