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.
kepis keps kewpies keeps kops kips koppies kapas kappas copies koppas capias copious cowpies guppies caps cops cups gaps
kepis pis epos veeps heaps hippies jeeps capias buppies beeps kewpies lapis nappies neeps peeps poppies peps repps cepes seeps speise spies deeps tawpies tipis weepies wheeps chappies cheaps chippies yippies reaps peise copies pips piso pies pias cowpies keeps pois piss guppies keps koppies leaps neaps pappies pepos puppies repos reps ceps sepias speiss zeps tapis tepas topis weeps whoopies cheapies cheeps yeps yuppies