Just thought of something that might speed this up a tad... a Disco 1 is essentially the same under the skin as a Defender or an early RRC, complete with 100" chassis and you can legally buy them in the USA. Why not import a recon/rebuilt/new chassis from somewhere like
http://www.richardschassis.co.uk - a galve one would be your best bet - buy a shot disco 1 in the USA as a donor and swap the running gear over. Swap the engine from the Ram into the new chassis and then add the Defender bulkhead and panels from a 2007 car? Essentially you're replacing the Disco1 chassis with a 'custom' chassis and changing the bodywork and engine... never know... might work

Would probably keep you busy until 2009 anyways