Self-supported? Carrying all your gear? Camping all the way? Cooking all the way too? With front and rear panniers?
What's your budget? If your budget allows, buy a touring bike. Any bike on the market sold specifically as a touring bike will do. Adventure Cycling has a list on their web site of such bikes, and the lastest issue of their magazine has a buyers guide. ACA will even give you a free issue if you request one.