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.
recaution reaction ruction rogation
caution recaution suction rogation paction legation reaction negation locution location liquation ligation vocation kation vacation cation faction equation auction action coaction ruction taction