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.
rifs riffs reifs refs reifies rives ruffs reefs roofs raffs revise ruffes refuse raphis reives rufous raffias raphias reviews roofies revs roughies raves roves
ifs coifs cuifs kaifs kifs naifs neifs reifs rifs seifs difs waifs