I've just gone the other way, selling my S4 and buying an Exige S
But I can understand why you want to do it the Esprit just looks so stunning even by todays car standards, and as a Grand Tourer it's a better car.
My suggestion is hop over to Lotus Esprit Forum, they have a huge USA following and the members there live, eat and breath Esprits and may be able to help you find one. (Hope posting this doesn't break any forum rules). Not suggesting you leave here merely ask them for advise!