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.
cypres cypress cyprus spares sprues spores sprees spires spireas spurreys suppress spiraeas spurries spars spurs sapphires spiers sopors speers sparse sapors speirs spoors spears supers sprays spruce sapours sappers sippers soapers suppers zappers zippers saporous sparrows spurious
apres cypres rappers peeries prees leapers capers copras ropers kippers japers lopers capris fopperies perries beepers pars aperies sprees hypers sappers presa hoopers coppers knappers poperies purs apiaries pores nappers lippers coopers prese mappers rippers quippers paupers guipures chippers wipers whoopers zappers whappers topiaries uppers diapirs spurs spurreys tapirs dupers spires shoppers yaupers shapers dopers suppers peppers press prez cyprus vipers oppress tippers spars rapers repress sippers sopors mopers hoppers depress pros cappers gapers jeepers sapors moppers coppras peeress papers hopers paries spores japeries parries pareus purees nippers gippers peres gawpers apers koupreys lappers preys pares boppers gyppers moperies cooperies wrappers vapors heapers lepers pyres pries copers pareos peepers poppers spares keepers reapers cypress loopers pipers tappers repros supers roperies sapphires soapers cuppers loppers zippers rapparees dippers naperies toppers cheepers whoppers whippers suppress weepers topers diapers choppers spurries sprues tapers duperies spireas shippers yappers yawpers