Can I use elementary's workspace switcher in Ubuntu?

Is there a workspace switcher for Compiz like elementary's? It's faster and nicer than Ubuntu's current one. Alternatively, is it possible to use elementary's window manager instead of Compiz?

I can answer one of your questions

  sudo add-apt-repository ppa:elementary-os/daily
  sudo apt-get update
  sudo apt-get install gala
  gala --repĺace

That will install gala the elementary window manager.

Is there a workspace switcher for Compiz like elementary's?

Typically workspace switchers are integrated in window manager. So, I don't believe you can use separate workspace switcher in compiz. I don't know of any workspace switcher independent of window manager

is it possible to use elementary's window manager instead of Compiz?

No. Elementary uses gala window manager. But if you try to use it, it will kill compiz (which in turn will kill Unity) because two window managers can't run simultaneously.