It doesn't matter which ports you have on your Titan. All he is doing is just running the AverMedia RECentral app in full screen mode, which is spanning the preview window across all three monitors, just like you can do with any other window when using Surround.

Don't get hung up on the HDMI splitter. He is not using it to connect any monitors directly or to split the signal. He is only using one output on it, and the only reason he is using it at all is to act as an HDCP stripper so that he can send the PS3 video signal to the Avermedia card via HDMI without the PS3 pitching a fit. You won't even need this at all to play games on either the Xbox or the Wii U (but you will need it if you want to use any HDCP enabled video apps such as Netflix).

His setup is as follows.....

PS3 (1 HDMI out) --> HDMI Splitter (1 HDMI out) --> Avermedia UC3 (USB 3.0 out) --> PC --> Monitors (via whatever connections you already use)

I am a little confused, but I am assuming that "home cable" was a typo for "HDMI cable" and am proceeding accordingly.

You monitors don't all need to be HDMI. If your Surround setup has worked up until this point (and based on your pictures in your first post it appears you have it set up correctly) it will continue to work with your game consoles as is. I would not go disconnecting any of the video cables you are already using for your monitors if they are already hooked up and working.

If you are using 4 monitors then they would already be connected to your PC like this:
2 of them connect to your Titan using DVI
1 of them connect to your Titan using Displayport
1 of them connect to your Titan using HDMI

If you don't have some laying around you will need some additional HDMI cables....one if you are just using a capture card, 2 if you are also using a splitter.

Connect you Xbox to the splitter input via HDMI. Connect the splitter output to the Avermedia input via HDMI. Connect the Avermedia UC3 to your PC via USB 3.0. There is no video cable that connects the Avermedia to your PC or to your graphics card, everything is routed over the USB 3.0 connection.

The video signal then goes from Xbox --> splitter --> capture device --> PC --> monitors over all connections

If you don't have a splitter then connect the Xbox directly to the Avermedia input directly via HDMI.

You will have to configure the Avermedia RECentral program with the proper settings. I'm not going to go into all of the settings (this post would be pages long) so use the setup wizard in the software and refer to the manual for your capture card.

When you have it configured correctly and you start the RECentral program you can take the video preview window and maximize it. In portrait mode like you have your monitors setup the window will span across your monitors and you can now play Xbox across 3 screens.