First off, yes. I know that a 4690k is WAY overpowered for something like an R9 270, but my Dad, who graciously got it for me for Christmas, pushed me to get something nice that will last me a while. (I think he also loves his own Intel 3770K too much) The cooler was a no brainer for the amount of money I had at the time, and works like a dream running push/pull with a pair of Corsair SP120s. At a stable 4.5 Ghz, I never exceeded 78 Celsius within Intelburntest on Maximum with IC Diamond 7C TIM.
The motherboard, which I was initially a little worried about, looking at Fatal1ty's unsteady product history, turned out to work beautifully. Overclocking couldn't have been easier, and the best part about it was that the driver disk that came with it HAD GOOGLE CHROME. NOT ONCE DID I HAVE TO TOUCH INTERNET EXPLORER! This a massive plus in my book, even though the rest of the stuff on the driver disk was pointless. The BIOS is great, and everything was already dialed in first time, recognizing my RAM and it's speed right off the bat. Looks good too.
The SSD is the best thing since sliced bread to a person that has only ever had mechanical drives. Boot up is so fast, I often struggle to get into the BIOS fast enough, and everything is just so... snappy! Mounting the SSD was a tricky choice for me, but after looking at some other builds, I found that little mounting point on the case, right next to the motherboard. This makes cable managment much more tidy, and if you are just running an SSD in your 200R, I recommend putiting it there and taking the front drive cage out.
The GPU was definitely a stroke of luck. Tired of the prices on Amazon and Newegg for new cards, I went to Ebay, and found R9 270s in all flavors for around 100$. I ended up choosing a Gigabyte variety for 90$, free shipping. It works perfectly. To anyone on a budget: try Ebay for GPUs! Just make sure that you're buying from a reputable seller that posted pictures of the card you want and wrote a description, and you can easily save tons of money on a GPU that works perfectly.
I chose the 200R because it was wonderfully cheap, and extremely well build and designed for what you pay, with dust filters for the front intake and PSU, and reasonably good cable routing options. I personally don't think there are better cases out there for the 50$ price point.
The PSU was quite easy to choose, as every build guide I ever watched on Youtube used some variant of the CX series power supplies, and they were well reviewed wherever I looked. I don't recommend looking for PSUs on Ebay, (you don't get the great warranties you get when you get one new, and there's no way of telling how old it is) but that's where I found fine. Note, though, that the first one sent to me was DOA, and another one had to be sent over.
The rest of the case fans I found for cheap, and look great in the system. If you don't care for looks, get Noctuas, but if you don't mind some more noise (I put voltage limiters on almost all of them) and you want a pretty system, these Corsair fans will do fine.
Building this PC was very easy in this case, and the performance i'm getting is phenomenal. I really only play more casual games, but if I ever decide to get into Battlefield or something like that, i'll know I'll have the firepower.
Sorry this was so long of a description, but I wanted to make sure that whoever sees this is well informed. If you have questions, feel free to ask, and if you have suggestions for managing cables in this case or other things, feel free to let me know!