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.
deifier defier defer deafer deffer differ daffier diver defray devoir doffer duffer devour
reifier deifier chaffier differ daffier jivier defier rifer reefier niffer miffier livier lifer leafier goofier beefier iffier huffier heifer fiver fifer buffier knifer puffier fiery whiffer chuffier fer fir