Wouldn't go with the Azodin, they weren't bad but it is just a cheap pump. The Carter would be the better out of the two, however it will be more expensive unless you know someone who is selling it and thats why your listing it. Otherwise look for a cocker that has been pumped (which makes it a sniper) you can get those pretty cheap.
CCM is a great pump but they will cost you.
An alternative to consider is the Empire Sniper, it comes with a spring feed, barrel kit, and it is set up for open class out of the box, play the hell out of it and then upgrade.