Can I suggest something not in your list?
If you want an 8 inch tablet, there's the Galaxy Note 8. It has an S Pen making it better suited for your sketching/painting needs. It also has a better processor and more RAM. I prepared a side-by-side comparison between the two 8 inchers: http://www.gsmarena.com/compare.php3...&idPhone2=5456

If your budget is flexible, I think you should also consider the Note 10.1 2014 Edition. I can't comment on the X86 processor of the Tab 10.1. Here's another side-by-side for the 10inchers: http://www.gsmarena.com/compare.php3...&idPhone2=5491 The resolution of the Tab 3 10.1 is pretty low for a tablet of that size.

By the way, don't you want a Nexus 7 2013 or LG G Pad 8.3?

But if I am the one buying a tablet now, I'd go for the Note 8.