I actually use an RF5. It sits next to my monitor at a distance from my ear that ranges from a foot when I am typing to two feet when I am browsing. Switch out those stock fans if you like, but only if you are dissatisfied with them.
The R5 comes with one fan in the front and one in the back. Since I remove the rear grill of all my cases (see, e.g., item 2 in my sig), I have no need of an exhaust fan. I put both in front.
If you remove your rear grill you can try both stock fans as intake fans. Swap them for new fans only if you are dissatisfied with your stock fans: you might like your Fractal fans.
For replacement 140mm fans I recommend, depending on your noise tolerance, the Thermalright X-Silent, Noctrua A14 FLX (it has 2 adapters that essentially give you three fan choices for the price of one fan), and the Yate Loon D14SL-12 (LED is optional; these are very cheap fans; you can afford to buy extra in case one clicks). I cannot comment on the Phanteks as I have not had a pair to test.
But if you get an R5, do note that the bottom filter pulls out from the front so you won't have to move your case if you have bottom intakes. The front of the case has a door so it is very easy to clean. It does have a rear "grill" that is too restrictive. Removing it gives you a quieter case no matter which case you use. I use two NF-A14 ULN's, but they cost me nothing. I have found they are only marginally quieter than the stock fans. I found that using two stock fans was hard to beat. YMMV.