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.
diffs difs dieoffs diffuse doffs tiffs daffs duffs deifies dives divas tuffs dufus defis teffs toffs defies devise davies doofus defuse devious divvies taffias taffies toffees toffies devisee diphase devs
biffs quiffs miffs tiffs jiffs diffs riffs whiffs ifs huffs buffos duffs luffs dieoffs muffs feoffs howffs difs gaffes doffs naifs reifs piaffes caffs offs puffs pouffes rifs ruffs daffs coiffes teffs waffs chaffs kaifs chuffs bouffes waifs raffs neifs effs seifs ruffes buffs guffs baffs cuifs coifs coffs cuffs kifs knifes toffs luffas quaffs fiefs pouffs boffs fifes gaffs kiefs boffos tuffs wifes chiefs naffs yaffs
diff dif daff daffy deify doff duff tiff edify