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.
suppose spouse sups supes soups sepoys speise saps sips sops spas spice spues spies sipes spays space soaps spaes spews spacey specie speiss spicey hyssops
appose oppose pappose reoppose suppose pose poise posse hippos papoose pappoose pappous pepos repose spouse depose