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.
ropers roperies rapers rapiers rappers reapers rippers wrappers reappears repours repress repairs repursue rapparees repros reprice reprise
apers dopers copers hoppers zappers whoopers toppers uppers whappers coppers diapers wrappers rippers dupers wipers hopers coopers sippers dippers shoppers paupers gawpers shapers mappers cuppers kippers knappers papers chippers supers tappers yaupers loppers gippers hoopers lopers keepers japers sappers heapers cappers boppers pipers nippers lippers lepers jeepers cheepers quippers topers ropers peppers rapers whippers weepers reapers whoppers capers tapers lappers nappers zippers yappers tippers suppers peepers poppers gapers loopers moppers hypers yawpers soapers gyppers choppers vipers leapers mopers rappers beepers shippers speirs pears reappears copras peers tapirs perse pros spurs piers peres coappears rapiers repros diapirs sopors purs coppras cyprus spars appears sapors apres spiers operas copperas spears pars peris vapors copiers capris cypres speers
roper ropery raper riper ropier roupier cropper groper proper propria dropper