Just another vote for the Sonex. I am building one from plans and it has been a great experience. If you are willing to go off of factory support there are ways to meet some of your other criteria for it. For fuel capacity some peple have built tanks that fit behind the seat for an extra 5 to 10 gallons. There was even a company at Oshkosh one year that offered tube tanks that fit down the forward wing rib lightening holes of the sonex. I want to say they were something close to an extra 5 gallons per wing. For the engine there are other choices besides the aerovee and jabiru, you just can't get sonex factory tech support for them. The corvair is a pretty popular and the honda Fit engine conversions are staring to take off as well. A rotax will fit on the Sonex. The only reason it isn't recomended is because the cost of the engine is pretty close to the Jabiru. As far as cross country capability just look up the name Aaron Knight on youtube. He has done some awesome cross countries to the bahamas, grand canyon, niagra falls, etc. All were done with two people aboard. The best suggestion I can give you is once you narrow it down to a few choices, go visit some projects in work as well as some owners who are flying them. You will learn alot more about what does and doesn't work for you in those short visits than you will on a message board like this one.
Keith