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.
fleech fleche fletch filch flesh fleshy flitch flash flush flashy fluish foolish
leech fleech leach lech letch belch bleach fleche fletch caleche pleach welch
flee feel file flea flew fley floe flue foley level levelly