I've been lookin at some top performance CPU air coolers such as Noctua NH-D14, Akasa Venom, BeQuiet Dark Star. The Noctua, for example, is very quiet and keeps the CPU at low temperatures so I'll probably pick that one. However, my worry about a lot of these coolers is the large area they cover over the motherboard, in particular that they overshadow the RAM. See these two pics:

Photo 1
Photo 2

With this sort of cooling unit installed, how am I supposed to change the RAM without first taking off the cooling unit and then having to re-apply the expensive thermal paste when putting it back on? I see myself now and again upgrading my RAM, adding more RAM, occasionally reseating my RAM (for any troubleshooting), etc, and am wondering how difficult or impossible it would be with such small clearance under that cooling unit?

Do ther people on here have this difficulty? Is there any other sink/fan coolers I should be looking at which are more low profile yet quiet and maintain low CPU temperatures?

Thanks.