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.
soys sos sows says sous souse sis syce sues sees sews seis seas saws sass cess sizy suss cissy sassy saucy seise sissy sycee
boys buoys foys hoys joys coys goys soys toys os