Specifics on hardware and software combinations for using an LCD monitor and a computer as a TV

I'm discussing all the pluses and minuses and ins and outs of combining TV with a computer.  I began discussing this in a prior question http://www.experts-exchange.com/Hardware/Q_21290722.html but as the range of the discussion has changed I've closed that question and opened this new one.  I  need a clear answer in order to be able to make a decision by end of day today.

I want my customer to be able to watch tv and work with his computer on the same screen, but not necessarily at the same time.  In fact I see no need for him to be able to use a screen within a screen, especially if this raises the overall cost of the system, since I gave him a fixed bid price on what everything will cost. Anyway he'll be confused enough by the computer alone.  

If he wants to watch tv he can do that.  If he wants to use his computer, he can do that and get a better clearer picture for the money than he can get anywhere else.  Using TV I assume the whole screen will be taken up by the picture.  It won’t be one of those small squares within a large black outline, as one gets with streaming video.

Money is an important issue.  I run a business.  I bought a high end Dell machine with many additional features and accessories.  (To push it to where I got a 40% discount on the whole machine.  Take a look at xpbargains.com if you're interested  The coupon code is SD58ZPBNN789SS for dimension desktops at Dell Home .)

I got a 256MB PCI Express™ x16 (DVI/VGA/TV-out) ATI Radeon™ X850 XT PE video card.   This doesn’t have all the features he needs to watch TV?   If that’s the case then that card may well be overkill.  (He’s an older individual, not a gamer by any means.)  If so I could take this card out of the system I bought, sell it and substitute another card.  Might this make sense?  What do you think?  

There’s another issue.  I don’t believe that the  UltraSharp 2001FP 20.1-inch Flat Panel LCD Monitor has a wide aspect, if that means it’s wider than it is longer. (description below.)  If this is true does it substantially cut down on the functionality of it as a TV?  Would my plan still make sense?

I’ve also found that for my older computer clients I have to radically readjust the size of icons, etc. when I have a very high screen resolution.  Will this cause any problems when using this as a TV, or are they totally independent of each other?

I also got Windows Pro for him, but Windows Home Edition comes with the Media Edition as a free addon.  Maybe I should have gotten that instead.  I’m not sure exactly what the Media Edition does.  Does it come with hardware or is it just software?    

And how about a monster cable, however that functions?  “MONSTER CABLE PRODUCTS INC Video 2 High Resolution S-Video Cable - 6.56 ft”  Should I get one of these?

Any other thoughts, especially as to the whole package/configuration would be much appreciated.  
Thanks,
Al


About the DELL UltraSharp 2001FP 20.1-inch Flat Panel LCD

Utilizing an Active Matrix TFT LCD, the Dell™ UltraSharp™ 2001FP Flat Panel Monitor displays sharp and brilliant images of text and graphics with a maximum resolution of up to 1600x1200 pixels. While its higher contrast ratio generates sharper, crisper lines and images, the wider viewing angle allows you to view the screen from various positions without compromising image quality. The Dell™ 2001FP features analog as well as digital (DVI) capabilities, providing connection flexibility. Apart from one upstream and 4 downstream USB ports, this display also features S-Video and Composite Video connectors. The slim bezel design of the monitor saves valuable work space. The combination of advanced LCD technology and the range of added features makes the UltraSharp™ 2001FP the perfect display for any user.

Diagonal Size: 20.1"   Viewable Size: 20.1"   Display Type: Flat panel display/TFT active matrix - desktop   Depth: 9.67"   Height: With stand: 25" (fully extended in portrait mode), 18" (compressed/locked in landscape mode)   Weight: 18.72 lbs (with stand and head)   Width: 17.6"   Image Max H-View Angle: ± 88° (typical)   Image Max V-View Angle: ± 88° (typical)   Analog Video Format: Analog RGB   Analog Video Signal: 0.7 Volts ± 5%, 75 ohm input impedance   Cable(s) included: 1 x 15-pin D-Sub and 1 x 24-pin DVI-D cable   Color Support: Yes   Compliant Standards: ENERGY STAR®   Connectivity Technology: Cable   Digital Video Format: DVI-D TMDS   Dot Pitch: 0.255 mm pixel pitch   Enclosure Color: Midnight Gray   Factory Preset Resolution Modes: 720x400 @ 70.1 Hz, 640x480 @ 59.9 Hz, 640x480 @ 75 Hz, 800x600 @ 60.3 Hz, 800x600 @ 75 Hz, 1024x768 @ 60 Hz, 1024x768 @ 75 Hz, 1152x864 @ 75 Hz, 1280x1024 @ 60 Hz, 1280x1024 @ 75 Hz, 1600x1200 @ 60 Hz   Front Panel Controls: Input Select, OSD Menu and Select, Minus (-) and Plus (+), Brightness / Contrast, Auto Adjust, Power Button and Indicator   Image Brightness: 250 cd/m2 (typical)   Image Contrast Ratio: 400:1   Lamp Type: CCFL (6) edgelight system   Max Operating Temperature: 95°F   Max Resolution: Up to 1600x1200 Pixels   Max Sync Rate (V x H): 76 Hz x 80 kHz