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.
cypress cypres cyprus suppress sprues spares sprees spores spires spireas spurries spurreys spiraeas spurs sapphires spars spruce sparse speirs sopors sapors supers speers spoors sprays spiers spears sapours sappers sippers soapers suppers zappers zippers
press cypress oppress depress repress suppress guipures pores sprees pyres spires pries peeress preys koupreys prees apres peres pares prese pross spares priss spores presa sprues cypres