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.
reoppose repose repos repps repousse reps roups ropes reaps repays repass rappees raps rips rapes ripes wraps ripsaw rupees
appose oppose pappose reoppose suppose pose poise posse hippos papoose pappoose pappous pepos repose spouse depose
repp croppie preop preppie preppy rep