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.
knops knaps naps nips napas napes neaps neeps nipas nappas nappes nappies kneepiece
knops ops biopsy coups goops kops loops lopes copse lops mopes bops knaps pops ropes hyssops sops dopas topes topos whoops woops chops poops naps copes oops hopes hoops fops loups mops cops hops nips opes coops opus popes popsy roups soaps soups dopes topis tops whops wops shops