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.
heavens havens heaviness
avens havens leavens ravens mavens davens heavens mavins dovens givens deafens sevens covens ravins evens venus veins livens pavins savins novenas faenas ovens deveins pavans wovens