garybrun
A good rule of thumb when looking for a tv screen is to hold both arms out in front of you.. fist clenched and thumbs touching each other in a 16:9 format.
Now if you fists fit in the screen edge to edge from your sitting position ... that's a good size.
Try it... anything over that is over kil and you will find your eyes will get tired look for images on a wider screen.
 
In my setup... my monitors (eggs) are about 1.40 x 1.40 x 1.40.
ill post a picture tomorrow if you require...   but I need to clean  my desk!!!  :-)
 

Glyn Barnes
I have no where near the size you are talking about, but I am not looking to view it from any distance. My consideration was maximum screen real estate so I went for a 27 inch 2560x1440 rather than 2 24" screens. I prefer a single screen and the vertical resolution of 1440 is a big advance on 1080. 
 
This is setup great sitting at a normal distance from the screen. I certainly would not consider a resolution less than 2560x1440 unless you are working with multiple monitors.
 
The Sharp in the link is just 1920x1080 so you are not going to get a whole lot on the screen even though it is 48".