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.
koss kos kousso kiss coss koas kois kusso kissy kis gos kas cos cows cosy keas keys goos goes coos kues coys kays kaes goys cuss goas kaas cusso goose gauss gassy goosy kazoo gussy guess cosie cosey quass
boss foss joss coss koss loss moss doss toss os