Forgive me for assuming this but the GT40 is beyond the reach of all of us. But perhaps there's a way to get in something around 40" tall with a V8 behind the seats for less than, say, a million. Find this 1965 Fiberfab Avenger GT for sale in Los Angeles, CA for $2,000 via craigslist.
Oh Fiberfab. Where would we be without your hauntingly beautiful customs that look mean but are no faster than a Bangladesh Tuk Tuk? I'll tell you where, in a world with less joy, less feigned extravagance, a world where I couldn't buy a GT40 replica with a 20 dollar bill and get change. Find this 1972 Fiberfab Avenger GT-15 here on eBay
currently bidding for $4,200 with a few hours to go, located in Fremont, CA.