The Corsair TX 850w is manufactured by CWT which has a reputation for good quality PSUs. Corsair also have some PSU models manufactured by Seasonic who has a reputation for building excellent quality PSUs.
The Silent Pro 800w is built by Enhance Electronics which is a OEM like CWT manufacturing PSUs for many other companies, but does not sell any PSUs under it own name in the retail market. I would say it's reputation is equal to that of CWT.
Both are good PSUs, but based on reviews that I've read the Corsair beats it by a small margin.