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.
zigs cigs zags zygose saigas zaikais sags sics zeks skis segs sikas zouks segos sicks sagos sikes sakis sagas zooks skies
bigs figs vigs gigs jigs migs pigs rigs cigs zigs digs whigs wigs