Unfortunately the Sapphire R9 280x is on back-order for most major retailers but I don't mind waiting it out.
I could really use a second opinion on the above configuration. I don't rebuild often (4-5 years) so I'd rather spend the extra money to do it right. As noted above, this will be almost entirely for gaming, starting with BF4.
-Better cpu cooler. You can overclock much better now.
-The motherboard has all of the bells and whistles you need.
-No real point in paying an extra $40 for the Sapphire one you linked (think it's the Toxic version). The Vapor-X is cheaper, fast, great cooling, and it's in stock. You're paying a lot more for better cooling, but the Vapor-X already has great cooling.
-Cheaper case. The 500R is a great airflow case. You can keep the 650D if you like the looks of it better.
-144hz monitor. 1440p monitors are quite expensive (~$500) and it'll be hard to squeeze it in this budget. A 1080p monitor should suffice for now and you can upgrade later. This monitor is 144hz so it can display up to 144fps. Great for FPS.
-Upgraded psu to 850w so you have the option to crossfire later.