My two cents worth......

When you go shopping for the hardware to build your new PC, whatever you do buy the best quality hardware you can afford since bad quality hardware is only going to create lots of headaches for you when you go to do your troubleshooting to find out why your new PC is randomly Blue-Screening (usually right in the middle of that important recording project-and you've forgotten to save/backup all the hard work you've done), something that's happened to me in the past and caused me a lot of frustration.

Also you want a CPU that provides a decent amount of processing power, the Intel i5 and i7 multi-core CPUs are good, get one that runs at a clock frequency of at least 3Ghz or so, be careful with Overclocking because you gain processing power but you may wear out the CPU and other hardware faster, if you can afford a motherboard that supports a decently fast Bus Speed definitely buy it (my motherboard supports a Bus speed of up to just over 2Ghz), the Bus speed determines how fast your Ram runs (the faster the Ram runs, the faster the data can be read into and out of the Ram, helpful when working with audio samples), you don't necessarily need to use a high-end Gaming graphics card when building a PC for a Studio, I seem to remember reading somewhere that some Digital Audio Workstations would crash if certain high-end Gaming graphics cards were used, maybe that's an issue that's been fixed lately.