There’s a lot of other things that make a gaming and audio computer different, outside of the video card. It comes down to many things - motherboard, chipset, RAM, cooling used, tweaks to the OS, etc. It is an involved process.
If you want to go 2011, you are restricted to some processors, some very powerful ones, but specific ones.
If you want to go to Intel’s 4th generation Haswell processors, you’ll need to choose a different socket size and processor type. I do not think you need to go Haswell, but if you want to, it opens different doors.
I personally use Gigabyte motherboards, AMD video cards (Nvidia for machines for video production), Kingston HyperX RAM, and varying processors depending on a client’s needs. You also have to take hard drives and their speed into consideration; are you going SSD, or using Hybrid hard drives? This is a big and important consideration. You also need to keep in mind that you want to put your samples/projects onto separate hard drives.
There are a lot of factors. There are plenty of DIYs and information on building a system to be found. Think about what you want to get out of a system, and feel free to PM me if you want to talk specifics.