Wireless extended display

I've been considering getting a tablet for the aformentioned purpose for a while now. I noticed iDisplay and Air Display are offering solutions for this. Are these viable solutions for:

-viewing pdf files 

-viewing videos

-using as music player remote

All of these on a home network, never more than 30 feet out from my router which is a D-Link DIR-632.

I'm using windows 7, and 8 at times.

If you have any answer or input as to what tablet/software one should get for this or need more info on my setup, let me know. Wasn't sure what section to put this in either...

Thanks,

If you are currently using windows. Not an ios interface, then go with android. I would suggest the new nexus 7 2013. It gets easier when you need to transfer information. just use a cloud like drop box. It also can link your tablet to your chrome account with a touch of a button send what you are looking at on your computer straight to your phone and viceversa, using "chrome to phone" and "phone 2 google chrome".