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.
cacas cacaos cocas caucus cocoas cocos kakas cocks cakes kaiaks quacks guacos caiques cuckoos guaiacs quaggas coax cogs coxa gags
cacas pacas cays caws case kakas lacks laics kaas macks micas ocas packs knacks picas ragas cycas sacs socas tacks takas whacks shacks yacks agas macs casa macaws hacks jacks cacaos cocas cocoas guacos vacs guaiacs quacks lacs backs pacs racks wracks sacks sagas decays tacos wacks chicas showcase yucas
caca cacao caeca macaco macaque