We have several links of this distance (actually 58-67km) and they all are reliable. As to the hardware you have selected, the 411 is a great choice, but I'd go with a 411AH. I have no experience with the R52 at these ranges but I can tell you that the Ubiquiti XR2 and XR5 are both capable of this range with no problems. One of our links is using RB333's with XR2's and 5 foot 30 db parabolics, it has been up since the day we put it up, hovering between -65 and -72. We have another link with a pair of XR5's on 411AH's with 28 db dishes and it performs almost identically.
You should be aware though, at these distances, throughput will start to fall off, we can run about 17 mbits across the single XR2 link is all. The XR5 link at 108 mbit will run about 33-35. Shorter links on our network exceed this by as much as 10 mbit so I think it's safe to say that the distance does begin to affect the link at some point. These are all single Nstreme links, the previous post about needing dual Nstreme is only if you need more bandwidth than what I just mentioned.