Helpful to mention a price range and you are looking for nothing less than 500W and all depending on your budget,a modular PSU is best. Then what sort of connectors do you need, mainly Sata with a few Molex? Do you need PCI-e 8 or 6 pin for a graphic card? 20+4 ATX connector with separate 8 pin EATX?
What is your motherboard and graphics card?