Which tablet/lap top would be best for my son?

I am trying to figure out what computer or tablet to buy for my son. He is disabled and in a wheelchair and likes to watch youtube videos. Also he can bat at the screen to "play" apps for babies… The kind where you touch the screen and fireworks go off or something else colorful and musical. He is visually impaired so I want something larger than the usual tablet. I have it narrowed down to 3, but I really need someone who is tech savvy to point me in the right direction. It would be mounted in one of those wheelchair computer/tablet mounts.

here are the 3:

the Samsung Galaxy View 18.4 "

and

http://www.amazon.com/gp/product/B00… A2V0AUEHW8YS8B

and

http://www.amazon.com/gp/product/B00…=A4UCFL9LU89NR

Thank you for any guidance you can give me.

Linda

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