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.
cuppa cuppy cup coup copay koppa coupe kappa guppy cowpea quippy quippu cop cap cape capo coop cope copy kapa quip
chuppa cuppa buppy huppah cuppy guppy kappa koppa nappa poppa pupa pupae puppy chuppah yuppy