Currently I have two workstations right now. A 980 + a 660, I use foremost for Gaming Videos + the later for Mild Gaming. The 660 is still pretty decent as I can Skyrim in High Detail fairly easy on Ultra Settings I lose a bit of framerate, but it's not too bad. Also saves on electricity using the lower-end PC for the most part!

The Love Shack(980 System) (I do want to upgrade to the 1080 now :/ LOL)
Operating System (OS) Windows 8.1
Control Processing Unit (CPU) Intel i5-4440 CPU @ 3.10Ghz
Random Access Memory (RAM) RAM 16.0 GB DDR3 1600
Motherboard (MOBO) ASUS Z-787-Pro
Power Supply Unit (PSU) Corsair CX 600M
The Iron Grenadier (660 System)
OS W7
CPU Intel Pentium G3258 Haswell Dual-Core 3.2 GHz
RAM 8.0 GB DDR3 1600
MOBO ASRock B85M Pro4/ASM
PSU EVGA 500B
To be honest of lately I've been feeling about cannibalizing my ASUS GTX GeForce 660 into the EVGA GTX GeForce 980 System as a PhysX Card.
My first system at the time without the 980 roughly cost me 1065 at the time, but I did have it discounted to 765 so I am a bit biased since I did have a deal sponsorship going on with ASUS + Corsair at the time. Which they even sold me a 660 at that time for 120 Bucks! But my new system with the 660 is relatively cheap. You might want to start saving up some money for a decently cheap system you'd be surprised about what you can get for only paying 650 Bucks right now.If your curious about my cases I'll list them - just lemme know.
But if/when you decide to build a PC if that's something you want... Always get the MOBO + CPU first those are the only parts that are really in my honest opinion that matter in the ways specs to the type of system you want to build. If you wanna head out to the AMD Side of things you'll find that you'll be saving some money 'typically'. I can't tell you what CPU is better than the other, but if you do go for an AMD PROCESSOR you won't be able to use it in an INTEL MOTHERBOARD and VICE VERSA. I recommend doing some research on your budget plan. But also take a look at usability. Usually when you want to build a PC it's for something that will last much longer than the ones that are generically made by companies like: Apple, Dell, ASUS, Sony, HP, Lenovo, MSI, Acer, etc. If you choose the generic route, please just please... Don't go with HP. ASUS, Acer, + Lenovo make some decent PC's IMO, but again I am a bit biased. My next PC is going to be an AMD and I'm not ashamed to admit that.
Other than that it's not hard to select the type of RAM you will need, but different boards and cpu's do have specific grades of speed of RAM it can take (or handle) So you might want to take a look at that. Then I suggest taking a look at alternatives for your system as I've said what whatever reasons you plan to go with it. Gaming might invest in a Water Cooling CPU System wouldn't hurt. I still use the stock cooler in my CPU and it's decent, but I've been heading towards that for awhile now. Power Supply is another matter if you don't plan to get a GPU in your system you can probably get away with a lower wattage unit. If your a neat freak you might want to get a Semi or Full Modular PSU so you can minimize the unnecessary cable issues you may or may not need use of or want.
If I missed something other than cooling fans just lemme know! I wanted 7 fans in my case and had to jerry-rig the fans with cable ties and directly port the power to the PSU itself. I ran out of case fans to plug into the MOBO itself.