Okay we have a price range 1000-1200, you are a gamer, and you want something to be upgrade-able in two years. Before you begin, you have to ask/answer more specific questions than that.
Are you putting the computer together? Do you have the tools? Etc. Research! Research! Research! Building a PC is learning experience, and you will be happier to know you chose the parts to the unit.
There is so many different options you can go with with that price range, and depending on what kind of games you play will determine what hardware you will really need. Something that can be further upgraded in two years? Well a lot will change in two years for computing. It depends on how much you are willing to upgrade.