What do you want to do with the computer? If it's an HTPC, it will do just fine with the 2GB of RAM it was sold with. Those RAM deals are great, but I don't think they'll have a noticeable performance improvement for most tasks.
The computer is going to be used for large numerical simulations so I'll definitely need lots of RAM to store the arrays. Also going to be using Virtual Box to install (possibly concurrently) several different OS's for testing. Thanks for the heads up though.
Have you had a chance to check if your RAM setting are unlocked in your bios? If so, the ones you linked are faster for only $5 more. But your computer should automatically use the faster settings for the faster RAM anyways.