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.
referrer reverer
referrer deferrer chafferer sufferer spherier severer cipherer reverer offerer quiverer quaverer coverer hoverer verier fuehrer fierier fearer waverer shiverer
refer referee reefer refire refry revere reverie revery rifer prefer