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.
sacra sacker scry scar scree score scaur scour sucre sugar screw scare saker scary scarry sicker soaker square seggar secure sucker screwy saggar scarey sagger scurry soucar sowcar sugary saggier saguaro suckier
sacra craw acre aquaria buckra fiacre jagra lycra macro megara micra nacre ocrea picara chakra