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.
coppras copperas copras copperahs coppers coprahs copers coappears cappers copiers coopers cuppers capoeiras cooperies capers capris cuprous kippers cupreous koupreys quippers gapers caprice gawpers keepers
coppras gippers copras cappers gyppers copperas rippers sprays sappers zappers operas poppers nappers dippers tippers moppers uppers loppers whippers kippers whoppers lappers choppers coprahs shoppers coppers hoppers paras tappers prase cuppers prays proas praus wrappers suppers sippers zippers peppers rappers boppers nippers toppers knappers whappers mappers whiprays quippers chippers lippers shippers praos yappers
coppra coappear coper copper copperah coppery copra coprah