I wanted to run a media server basically to stream video from internet and from hard drive like Kodi

Also I need to use it as a torrent machine, with Utorrent or deluge (recommend a better one)

And use it to store and access files remotely may be via FTP server or by my own cloud. (Can u please tell me the difference between the both, and which one you prefer)

Also vnc to use it in headless mode may be with real vnc or other (Recommend)

If possible, to run my own VPN server for private use.

May I run all in one pi. Will it work fine???? How will the performance be than?

Or do I need to get different pi for each job or a cluster to increase house power????

My initial suggestionsfor the OS was thanks to you guys, rasbian, dietpi, openle. Suggest me how am I with that.