It's now common knowledge (to us Gurus anyway
) that Ryzen performs best with fast memory, the faster the better, so, yes, as has been said, try to go for DDR4 3000.
The stock r5 1600 cooler isn't actually that bad, I suggest you run the system with that and see if you really need to spend extra on an aftermarket cooler, besides, the money saved will more than cover the cost of faster memory which will have a larger impact on performance.
What will you use the system for? You have paired a very strong CPU with a quite weak GPU, if it's for gaming I suggest you hold off and save a bit longer and aim for at least a GTX1060, unless you just play less demanding titles or just game casually that is.
Think about adding at least a 64Gb SSD into the mix, I know I'm spending your money freely here but even a tiny SSD like that will hold Windows and a few bits and pieces and the difference in system responsiveness is nothing short of breathtaking if you're used to HDD load/save/boot times.
The above are suggested improvements, the build will work just fine as it is.
One last point: I have suggested upgrading the build to include a GTX1060. Now is a truly terrible time to make such a purchase, cryptocurrency miners have been buying up GPUs worldwide for some time so there's a BIG shortage which has pushed prices of the stronger cards up ( and sent the prices of AMD RX480/580 through the roof). It's not effected the GTX1050 class so you should be fine if you want to stay with that choice but the GTX1060s' ARE more expensive than they should be right now.