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.
stupas setups situps stoups stupes steps stops stapes steeps stipes stoops stopes stowps steppes
stupas dupes tittups getups dups tapas taupes tepas tups photopias dopas cutups letups metepas outpass setups situps stoups stupes utopias
stupa stupe setup situp step steppe stipe stop stope stoup