First, the P8H61 M LX Rev 3.0 only supports DDR3 1333 ram speeds, if you put a DDR3 1600 stick or sticks in it will simply downclock the ram to 1333. You would have to go into the BIOS to setup the ram to get faster speeds.
Your better choices here would be to simply find a 4GB stick that matches your existing ram or buy two new 4GB sticks. You could likely find a 2 X 4GB set for about the same price as the single 8GB stick you listed. By installing 2 sticks you will take advantage of dual channel mode which really speeds the ram up. I have listed a couple of examples below, don't worry about the fact that they are listed as 1600MHz, they will run fine at 1333MHz and can be made to run faster if needed. They also have faster...