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.
cercus circus circusy seracs sarcous zerks cirques
arcus circus cercus torics tarocs drugs seracs circusy arcs mercs frugs recs recuse rocs ruckus barcas turacous rugs raucous narcs orcs trugs torcs crocs durocs verrucous darics sarcous crocus percuss argus orcas narcos marcs lyrics shrugs