Diesel Bombers - Convert Excursion 6.0 to Cummins 6.7?

I have had about 190,000 trouble free miles out of my 6.0 but I feel that my run of luck is coming to an end. Was looking at Dodge trucks because I have heard so many good things about the cummins durability but I don't think I can live with truck. I mean that interior....seriously??? Anyway I absolutly love my Excursion and would love to drive it for years to come. After doing some checking I found the Fordcummins site and I see these coversion kits. Has anybody seen or done one of these conversions? Can you put a 6.7 in a Excursion? Which would be better 5.9 or 6.7? 12v or 24v? I am relativly new to the tuning, all I did to mine was a Mgna-flow exhaust to turbo, AFE intake and Superchips tuner. Kind of wanting to take it up a notch. Any comments or opinions would be appreciated.