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.
repour repro reaper repair roupier reappear raper riper roper rapier rapper ripper ropery ropier wrapper
pour vapour repour sapour pur puri spore vapory sopor sapor guipure pure vapor vapoury pore poor spoor purr spur
repo rep reap repay repp arepa crepe crepey crepy preop prep prepay preppie preppy