Don't mean to take away from the tribute kits but with your build experience (and possibly budget) you might consider doing a more exact replica 250swb. Have you seen what mirage auto is developing? You might be able to use a factory five cobra chassis and fit the mirage gt250 body to it. Then pick your running gear and set up the interior how you like.
https://www.facebook.com/mirageautodev/
http://mirageautomotive.co.uk/mirage...uilding-a-kit/