That looks like a pretty sweet setup. It's exactly the sort of computer I would build myself (and in fact is very similar to the one I have built myself).
One thing that jumps out at me is that your power supply is a bit feeble for the computing power it's supporting. According to
this page, the Radeon R9 290 has a recommended minimum power supply of 750W. Various other sites around confirm this. I know partpicker esitmates you're fine (just), but do you want to risk it?
More importantly though, that graphics card requires two additional power connections from your PSU: one 6-pin and one 8-pin PCI power connectors. Your chosen power supply does not have both of these. Look carefully at the specifications of the power supply you choose to check for these connections. Follow links to purchasing sites (like CCL and Scan) if need be as these may provide more info. (NB: 8-pin power connectors are sometimes marked as 4+4 connectors)
Your RAM is faster than your motherboard's RAM slots. This isn't a big problem. The RAM will just go at the fastest speed the motherboard will let it. But you might be spending money on the fastest RAM unnecessarily.
Were you planning on using any CD/DVDs? If so, an internal drive might also be a good idea.
Is an operating system on your list of things to buy or do you have something lined up already?
Edit: and one minor little thing before I stop poking holes in your nice pc: your motherboard seems to only have 1 fan connector on it. The manufacturer doesn't state how many but I looked at a picture of it and I could only see one. Your case comes with 2 fans included (with space for more). You can get a
molex to fan-plug adaptors, or just not use one fan.