If he can out hit you, I would used topspin looping balls to push him back and the go with low slice to force him to bend low. Also, use wide forehand to put the big guy on the run if you get a shorter ball that allows you to get your feet into the court at contact. Stay away from the angles if have both feet behind the baseline.
You say your serve and return may be better. Well, keep your hands loose and try to generate pace and spin off serve and return when you have the chance. If you hit a quality ball first, maybe you can get the big guy on the run.