Re: Would buy a new smartphone to install ubuntu
No one here (or anywhere else, for that matter) can tell you with any certainty when a smartphone running Ubuntu natively is going to be available.
And, Canonical has made it clear that they are NOT going to release an installable version of Ubuntu for Android to the general public.
If you know which Android phone you want to use, my suggestion is to go to the Android forums, and to the Phandroid forums, and look through their sections for those dealing with your selected model phone. They often have sections dealing with Rooting phones, and you might find something useful there.
Ubuntu 16.04 Mate, Mint 17.3; MS Win 8.1, MS Win10 Pro.
Will not respond to PM requests for support -- use the forums.