Question [Q] Installing Linux OS onto Android - what device is ideal?

Hi all,

I would like to install Linux OS onto an Android tablet, but am not sure which tablet to buy?? (brand/manufactures, processor, RAM, storage etc?).

I am looking at a 7" screen ideally, and as I'm on a tight budget, I can't spend more than about $70 for the device.
I will also be adding a wireless keyboard, so as to maximize on the screen size.

Also, I understand that I will need to 'root' the device.... so I ideally need to buy a tablet that is known to be able to 'rooted' ...?

Which version of Linux is the best for Android tablets? (my main objective is to be able to successfully install & run Linux video-editing/movie-making software, such as OpenShot...?)

I had a PendoPad tablet (7", Android OS Version 4.0 Ice Cream Sandwhich), and it was very good for the price. Has anyone used such a tablet for this...??

Any help would be much appreciated