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.
sierras sirras sirrahs surras serais sieurs sers sirs serries sirrees sires suras seres suers sears seers soras serosa serows surahs serous cerias sirees cirrus series serosae sauries soirees cirrose surreys sorrows cirrous serious seeress sris ceros saros saris soars ceres sorus sours sores xerus zeros cereus cerise cerous ceruse sarees zeroes souaris
sierras terras eras errs whereas terais derris surras sirrahs murras kerrias jarrahs gerahs durras cerias hurrays eyras erase arrays arras serais ferias sirras derays hurrahs sherris ras ers
sierra serry sieur sirra sirrah sirree osier sizer ser sir