Asus P7H55-M-Pro & Buying new Video Card

[GhostWar38]

1st question is what video card fits in this motherboard that is "new" and good enough to play games on?
2nd question is how do I keep my PC in my office and run the games to my 60 inch LCD in my living room?

My friend built this PC for me. I'm an idiot. This is what I know.
I have:

• 
  Motherboard by Asus P7H55-M Pro.
  Processor by Intel Core i5 750 2.67 Ghz
  RAM 4gb
  64bit OS Windows 7
  Realtek Audio
  Video Card NVidia GeForce 7300 SE/7200 GS
  Power 700 watts.

What I want to do is start playing games on my PC. I only will really be playing COD and Assasins Creed so I'm not a huge gamer. I am looking into "Steam" too. I understand I have to get a wireless controller too as I prefer this over the keyboard and mouse. I also play on cutting my cable and watching "internet tv" in my living room.
Please someone help me!

 

[inzone]

Most likely you could get a GTX 660Ti video card from Nvidia or from AMD a HD 7870 , anything higher and your CPU will be a bottleneck.
The office is where in relation to the TV ? They do sell long HDMI cables but it would depend on how far it is between the TV and the office.
The wireless controller would have to be relatively close to the computer for it to work.

 

[GhostWar38]

Most likely you could get a GTX 660Ti video card from Nvidia or from AMD a HD 7870 , anything higher and your CPU will be a bottleneck.
The office is where in relation to the TV ? They do sell long HDMI cables but it would depend on how far it is between the TV and the office.
The wireless controller would have to be relatively close to the computer for it to work.

Do I have to be concerned about PCI 3.0 in this new card? I believe my motherboard is only a PCI 1 or 2 express gate? I don't even know what that means.
I might just have to move my PC to the living room if I can't find an alternative.

 

[inzone]

The video cards are backwards compatible so they work fine in Pci-e 2.0.