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.
dufus duffs doofus defuse difs diffuse doffs tufas diffs defis tofus daffs tuffs defies defuze deifies devious dieoffs doghouse devs doughface
dufus kufis chufas tufas cuifs doofus defuse rufous refuse puffs poufs pouffs muffs luffs guffs fuse feus cuffs huffs effuse buffs fuss ruffs suffuse diffuse duffs tofus tuffs chuffs