I would go with the Noctua NH-D14 for about the best cooling vs noise. It would have about the same clearance as would most other top line air coolers like the Mega, TRUE or VX. The clearance should cause no problems.
Possible clearance could be more with the motherboard between the NB hs or tall ram sticks.
You can look at that pic of my case and see that my true covers 1 ran slot that if I used it would require a normal sized stick.