Re: Best tablet'r to install ubuntu on.
The original Nexus 7 (not the new one yet as far as I know) and the Nexus 10 are the only officially-supported tablets for Ubuntu. You might be able to find both of them on clearance actually as they're superceded / about to be superceded.
Pretty sure the new Nexus devices will be supported soon.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.