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.
capiases capizes copses capsize coppices capacious gaposis
capiases appeases tapises speisses repasses lipases lapses lapises bypasses apses poises paseos pisses peises peases pauses passes pases speises diapauses upases