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.
rupee rappee rape ripe rope roup ropey roupy rupiah rap rep rip reap repo repp ropy wrap
rupee toupee pee peep whoopee epee veepee jupe coupe loupe rappee supe dupe taupe teepee tepee topee pupae yippee