those cards/units that you show are meant to be used to watch tv from cable television, not the internet... you'd plug the tv cable into the device to watch regular cable or antenna tv on the computer so they would not be useful for what you want.

What you do need is a new video/graphics card that has more than just the vga/computer monitor output.

For that I'd suggest asking advice in the hardware forum because there are a lot of details in both figuring out which one would work and how you'd install it. It would be an improvement from the existing built-in card but the install is not always simply just plugging a new one in and there are a number of factors that need to be sorted out before you even start.... like the model of the motherboard that you have in the computer.