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.
stupes setups situps stapes stipes stopes stoups stupas steppes steps stops steeps stoops stowps
dupes stupes taupes retapes teepees tepees stoups stipes stapes setups cotypes topees letups etapes dopes dups topes watapes neotypes toupees tapes situps potpies tawpies tups stupas stopes steppes types metopes tittups retypes cutups getups biotypes biotopes atopies wattapes
stupa stupe setup situp step steppe stipe stop stope stoup