I designed this custom build so it could be upgraded in the future. I chose 16GB of ram because converting videos and recording take up ram so with the 16 GB you should be fine. The video capture card is just an idea. they are good if you are hard core gaming/recording because it takes a load off the system
Depending on the games, you should upgrade to 16 GBs of RAM. You should be able to add 2 more HDD/SSD. I recommend using Fraps or Dxtory for best results with this build. Don't try to OC without getting a better CPU Cooler.