yes he will be in macalania woods, on the stretch of path between the southernmost save sphere and thunder plains.
you can also fight ultima buster for weapons with triple overdrive, overdrive -> AP, and triple AP. however, this is a hard fight. i would recommend just getting triple AP weapons from one-eye for three characters, level them up, then use those 3 to kill ultima buster for the weapons. the 3 chars i level up r wakka yuna n tidus (wakka=attack reels tidus=blitz ace yuna=sacrificing aeons easily
)