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.
capias caps capos kapas capiz capes kappas cuppas copies copious cowpies cowpeas gaps cups cops copse gawps coups copes gapes coops kepis copays coupes coypus koppas coppice coypous guppies kewpies koppies
pias sepias capias pas pis pass paws kapas piss nappies papaws pays pase paps pips piso nappas nipas papas puppies pappies tawpies yippies chuppahs cheapies whoopies upas tipis tapas poppies spies spas lipase napas repays cowpeas kepis opahs copies copays buppies kewpies pois kappas bypass guppies lapis cowpies rupiahs huppahs cuppas koppies hippies repass peas koppas pies pawpaws poppas pupas spaes spays dopas tapis tepas topis weepies chappies chippies chuppas yuppies