First of all, CX series is the weakest PSU series made by Corsair. It's lifespan is lower. They are pretty good, but you might end up having some energy problems, or lack of reliability in about 1 or 2 years.
TX series is some what enthusiast, it's efficiency is higher and they last for a longer time than CX.
You could always check Tomshardware for what products are recommended and what products are a trap. Either way, I wouldn't buy any of these. I'd go with a ZT from OCZ, Cooler Master or Antec.
Reason? I had several PSUs made by Corsair, and most of them, lasted for less than 2 years. And I can asure you that they had a higher wattage than the recommended for my previous system. No to mention that they are noisy as fuck.
My true recommendation is OCZ.