I'd go with the cheaper of the two and here's why:
1) The APU isn't a steller overclocker so you'll probably reach the same result with either board.
2) FM1 is done, they are already making FM2 for the next generation of APUs.
3) 1866MHz will be plenty of bandwidth, and 1866MHz RAM is expensive.
4) Do you plan on throwing in a HD 6570 for some CrossFire? If so I don't see you using the second PCIe slot for anything needing more bandwidth than PCIe 4x (i.e. sound card, RAID card, ethernet, etc...).
I built my friend an A8-3850 (before the unlocked SKUs were out) and I was impressed with the build.about35757.html