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.
horst horste hurst hoariest horsed hirsute hairiest hearsed harassed
horst worst purist frosty rearrest forest verst verist nearest prost prest aorist corset hurst lyrist serest roost grist sourest roset dearest fairest direst rust drest wrest tourist roust tryst crust wrist airest sheerest roast curst frost aerosat queerest searest querist horste jurist verste poorest merest prosit frowst verset first rarest rest worset purest karst sorest burst surest erst diarist aurist dourest arrest durst barest trust crest wurst yarest
horse horsey horsy hers hoars hoarse hoers hoorahs hoorays horahs horas houris hours ahorse