The only thing I can think of is you may want to check the RAM clearance on the Noctua with your motherboard. I can't think off the top of my head if the final slot allows for the RipJaw X series heat sink. Regardless you can put it in the first and third slot (the pair furthest from the CPU) and be just fine.
Are there any disadvantages of using the other slots? They will still be in colored matched slots so im assuming no?