Whether it is overkill or not has a lot to do with what you want to do with the computer. If you're going to use it for getting on the internet, playing basic windows games(i.e. solitaire), keeping track of your checking account and running office programs then it's probably serious overkill. On the other hand if you're going to use it to edit videos and and create music then it might be a little under powered. If you're going to use it primarily as a gaming machine then it's about right. BTW, I noticed you are buying a Keyboard and Mouse plus an OS. You might want to look into a sound system if you don't already have one.
As far as it being future proof, +1 to what aqualipt said.