SATA splitter or molex to SATA?

So I have a cx750 power supply from Corsair. However it only has 3x sata connector and 2x molex. Now I'm a storage noob so I don't know if it's preferable for me to buy a SATA splitter or if I should buy a molex to SATA adapter (I've heard negative things about doing this). Any help would be appreciated.