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.
whoop whop whoopee whoopie wop whap whip whup whaup wheep whippy wap weep wipe
hoop whoop hop hope coop goop goopy loop loopy poop whop chop shop