- Corsair CX500
CWT design, nothing special, middle of the pack for noise.
- Antec HCG620-M
- Corsair TX650(V1)
They're both based on the Seasonic S-II design, the Antec is modular. If there are a lot of connectors on the Corsair you don't use, cable Management with the Antec will be easier. Of these three I would choose the Antec.
Are those the only PSUs available? Newer models like the Seasonic G series cost roughly the same as the above models and are better electrically and acoustically.