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.
softas softs soffits softies sifts soviets safeties sights savates sapheads seafoods sightsaw sightsee
softas haffets tufts tofts defats efts sifts pooftahs lofts refits lifts lefts gifts hefts hafts shafts wefts haffits fads rifts whiffets wafts tuffets taffetas softs soffits rafts fats muftis fetas fets fits befits buffets shifts
soft softa softie softy sift soffit