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.
cess cees cease cissy sos cis sis zees syce sues sows saws sews seis sees seas sass sice says sous soys suss saice sassy sauce seise sissy sycee zoeas
ess fess jess guess less loess mess ness cess chess es