Will it be hard to transfer data from CDN?

Currently my web pages and all the user uploaded images are at the same location. Now I want to move all these images to CDN. But I could not move further because of the following clarifications required.

1. Who is the best CDN provider?
2. If I use Amazon S3 for storage and CloudFront for CDN, will there be a possibility to move to another provider easily to dump S3 data to other storage mechanism? Consider that the storage volume is nearly 1 TB of images. How can I dump this data to other storage mechanism easily?
3. If I use cloud storage for storing my images, will there be my control and guarantee for my data? In such case, if I want to move to any other cloud provider, what are the different wa开发者_开发技巧ys for this transition.

1. that's arguable, for me amazon dose the trick
2. you can easy move files in and out of S3. You can use one of the tools out there (s3cmd, bucketexplorer etc).
3. I know they have a 99,99999 guarantee but you can always use your personal server/storage as the origin for amazon CDN, it's not necessary to use S3.