Building a gaming PC

it's a great gaming PC :)

Wait steam http://www.3djuegos.com/noticia/137365/1/especificaciones-tecnicas/steam-machines/300-usuarios-prototipos/ , here you have the spec.

I would say wait for amd to release their new range of graphics cards later this month and get he R7 260x it will be quite a bit more powerful and will be in the same price range as the HD 7770. I think that some of them will be releasing as early as next week.

Op, are you trolling?
I ask because you linked an AMD Socket FM2 CPU, and then an Intel Z87 Motherboard.
You cannot put that CPU into that Motherboard. Not only is it not supported, but it's physically impossible since different socket types will use totally different numbers and layouts of connecting pins.