The CPU/sink is the first thing you install when you are building. If you want to install a sink that requires no backplate you will have to settle for a mediocre cooler.
The only cooler that I can recommend if the freezer 7 as long as you do not go crazy with the overclocks. The freezer 7 is overpriced for what you get so choose wisely!
I strongly recommend that you remove the board and install a cooler that requires a backplate unless you will be running your CPU at no more than 3.7/3.8Ghz.