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.
perps preps props preops hyperopes hyperopias prepays priapus purpose porpoise preppies prepuce pyropes
perps bewraps creeps carpus carps corps harps fraps herpes sirups drops props dorps tarps preops trips larrups urps grips chirps crops sharps corpus raps arepas drips craps crepes repos repps corpse rips wraps reps syrups hydrops reaps rewraps traps preps turps burps warps kreeps chirrups gorps sherpas
perp prep prepay preppie preppy prop