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.
cassias cassis casas quassias casease cases casus cussos cusses causes gasses cosies quasses cuisses caseous causeys gussies caseose gausses coses gases coseys kisses kussos gaseous guesses koussos
cassias quassias wussies tussahs dassies sassies pussies missis missays massas lassis lassies gussies cassis isseis hussies hissies fossas essays bossies bioassays assays assais lyssas messiahs missies poussies cissies sissies tassies tussis chassis sis