I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
preops preps props prepays propose pyropes perps preppies hyperopes hyperopias prepuce priapus purpose porpoise
preops repos troops hydropsy dropsy droops pyropes preps perps liriopes repps reps ropes roups arepas reaps creeps crepes crops croups gorps gropes groups kreeps hyperopes corps props dorps drops hydrops towropes tropes
preop prep prepay preppie preppy prop pyrope