ef - a fairy tale of the two [Eng] (Mangagamer version)

So if I get it right here is only half of the game(first tale). In this case where can I get the second part of the game? Is it also officially translated?

The second part wasn't released yet and it will probably be a while before it is released. The only fully translated version of the game that you will find is "ef - a fairy tale of the two." released by NNL, not by mangagamer.

NNL combined this and the latter tale together into their ef Lite release. The only differences would be a more polished translation, less mosaics, and the lack of the NNL-added troll ending in the official release. Go with this first if you want to enjoy the best quality release, or go with Lite if you don't want to wait for the second part's official release.

the second part is Ef - the latter tale.
I think you should wait patiently, the latter tale is being worked on by mangagamer(official translated) it surely will released in 2013.

Ef - the latter tale uploaded. Just scroll down on the first page.

I'm aware that links for the first tale are dead. I'll try to re-upload it soon. Re-uploaded. Meanwhile, a torrent for it is available here

On another note, it's a real shame minori not allowing Mangagamer to do physical copies of this VN. I'm sure that a limited edition would be beautiful.

What is the difference between these two separate stories and the combined story? I already downloaded the latter, so I wanted to know which among them is the best.

There's an explanation three posts above yours.
Directly answering your question, the official release is better.

Alright. Noted. I will just wait for the first part download links.

If you don't feel like waiting you can download the torrent.

Ef - the first tale uploaded. Check the OP.