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.
gawpers gapers capers cappers capoeiras coappears capris copers kippers coopers cuppers coppers copiers keepers copperas guipures quippers cooperies copperahs caprice cuprous
gawpers yawpers appears capers papers pears wipers rappers loopers pipers topers perse copers zippers peepers japers cuppers piers peers peris beepers ropers copperas loppers reappears mopers apers gippers yaupers shoppers chippers whoopers uppers tappers dippers suppers rapers shapers speers whappers coappears dupers spiers peres sappers kippers soapers lepers knappers lappers whoppers boppers paupers operas moppers lopers copiers rippers gapers heapers hopers coppers hoppers reapers gyppers jeepers coopers vipers tippers peppers lippers rapiers quippers yappers zappers dopers nappers hypers spears leapers sippers keepers wrappers hoopers speirs cappers shippers weepers mappers choppers poppers supers diapers tapers toppers whippers cheepers nippers