http://oblivion.nexusmods.com/mods/28378/?tab=2&navtag=%2Fajax%2Fmodfiles%2F%3Fid%3D28378&pUp=1

Look into the download "part"
Am I obliged to download the omod , because it seems that there is no part 2. Am I wrong?

It would seem you are right.

An alternative download with all four parts appears to be posted in the comments, http://theelderscrolls.info/?go=dlfile&fileid=298.