I decided to switch to the new LTS Ubuntu 14.04. Due to the low network speed downloading it will take some days. So it take some time to get the new Ubuntu after release. To avoid the delay I decide to download right now.
The plan is start download currently available iso image (alpha, beta, daily build or something else I don't know) from http://cdimage.ubuntu.com/releases. After downloading iso file, download the .zsync file, which wall be available after the final release. Using that .iso file and .zsync make the final release as described here.
The problem is I don't know which iso file should be selected to download. There are many files (alpha, beta, daily build or something else I don't know). AFAIK .zsync files made from different base files will be different.
Which .iso file and .zsync files should I download to make the final release of Ubuntu 14.04
edit : from the comment from @the_Seppi, I understand I can use the same zsync file for alpha, beta, daily builds. Am I right ?