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.
chuddar chudder cheddar cheddary chadar shudder shuddery chadri chador cheder chider chowder shedder chatter cheater chattery chattier shoddier shader chitter shadier shatter shouter shutter
chuddar budder feudary judder mudder rudder sudary udder cheddar cheddary chudder shudder