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.
shittahs shits shotts shiatsu chetahs cheetahs chitties chits shuts shads shots sheets shouts shotes shades chotts shoots shutes shoats shadows shiatzu chuddahs shoddies sheds chides
shittahs bettas cottas lotahs lyttas pittas suttas cheetahs chetahs tas
shittah shitty shit chitty shott