i have a similar body type (6'4", 220lbs, big thighs from years of lifting/athletics) ... i like Nautica's "Big EZ" jeans because they have a full cut in the thighs and seat w/o looking too baggy/sloppy. they come in many colors/finishes (they don't all look as worn as the pair in this photo)
i usually have no problem finding them in Macy's.