Re: Advice for Building a Linux Gaming Computer?
Nvidia GPU, definitely. ATI GPUs are total rubbish on Linux because ATI's drivers lack features. ATI also removes support for anything more than a couple of years old. You are probably safer with just one Nvidia card, not an SLI setup.
As far as distros goes, "Windows-like" shouldn't be your main concern. The quality of the distros, the hardware support, how easy is it to install Nvidia drivers, how easy to use generally, how much software is in the repositories, whether there is a big community who can help you if you get stuck... that's the things that matter when choosing a first distro. Not "does it look like a Windows desktop". 'Cos it certainly wont work like one!
Ubuntu is a good choice for all the factors I listed. You couldn't mistake it for Windows but it is pretty consistent and easy to use.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.