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.
foss fosse fossa fossae foys fuss fess foes fussy fesse fas fes fees fehs feus foci fozy fuse fays voes vows fease fusee
boss foss joss coss koss loss moss doss toss os