The processor you decide to go with is going to depend solely on your own needs, ie: cost, performance, brand loyalty. If a game is ported to PC, it is going to work on AMD and Intel chipsets. So go with whatever's on sale, or whatever gives better benchmarks at the time. There may be some marginal improvements in quality, but ultimately, it won't really matter all that much.
In certain cases, graphics cards may contain manufacturer-specific technology that doesn't necessarily translate as well to other cards - "TressFX", "PhysX" - but those won't affect your ability to play the game. They just change how the game is displayed, and in some cases, driver updates can resolve the issue.
If you're outputting to your TV, streaming won't be an issue. Just treat your TV like a monitor and you will never have issues with file formats again.