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.
wimpy wimp whomp whump
jimpy gimpy wimpy imp gimp champy campy hempy wimp simp lumpy mopy bumpy vampy humpy guimpe limp limpa jimp pimp jumpy impi dumpy chimp