You should buy the game for Xbox. It's alot more convenient sitting in a nice sofa playing it with a controller in your hand. I always feel uncomfortable sitting for long periods in front of my computer with my arms stretched and what not.
I also feel more "into" the game on console. Dunno why.
You can hook up your pc to your tv and do the same thing. It amazes me that many player cite using a controller and playing on the couch as reason to choose console over pc, or they cite very exaggerated costs. Many people are not well informed about pc gaming.
Console exclusives are a good reason to get a console, playing with a controller,etc is not.
I myself play on pc and I don't sit upright in front of it, I don't know how other pc players do that its so uncomfortable. I have a set up were my feet are on the end of my couch and I am leaned back in my chair, its basically the same position I would be on the couch.
My wrist and arms are fully supported as well in this position, no strain.