PC - 128000 / 1600 MHz RAM is what you are looking for. I don't know how much RAM you are looking for but it is strongly recommended that you buy the RAM in a kit if you are upgrading. Mixing and matching your RAM can cause problems even if the speeds match. Also with kits you get dual channel mode.
Go to a ram vendor web site and access their ram upgrade app.
The major vendors like Kingston, corsair, G.skil, patriot... will have one.
Enter your PC and you should get a list of supported upgrade kits.
If you subsequently have a problem, you will get support.
PC - 128000 / 1600 MHz RAM is what you are looking for. I don't know how much RAM you are looking for but it is strongly recommended that you buy the RAM in a kit if you are upgrading. Mixing and matching your RAM can cause problems even if the speeds match. Also with kits you get dual channel mode.