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.
sicko sick socko sic sickee sickie sika sike suck scow sock sack sucky sky ska ski sec suk sac syke sago sake seek skee skew soca saki sook souk sego skua soak soke zoic
sicko ick chico wick wacko dicky socko wrick kicky sick rick pick nick mick lick kick quick picky bucko jocko gecko icky hoick hick fico cuckoo dick tick whacko chick shacko