When I built my touring bike it was more for winter training than long distance riding. But I found an old Trek 520 frame from the early 80's made of steel. Then put some Dura Ace components on with bar-end shifters and a Brooks saddle. Those saddles have to be beaten up pretty good to break them in but there really is nothing better for touring.
Total cost of rebuild was just under $1000 and it turned out to be a really sweet ride!
-AJ