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.
sashay sash sauch sushi
shay sashay sha shy mashy washy fishy dishy gushy bashaw pushy cushaw poisha cashaw mushy geisha shah cushy shaw chay kasha meshy pasha pshaw rushy ashy dashy bushy tushy shea wisha