I don't understand why you are so confused/concerned. You have stated your use case and IMO, they are not too demanding. Question now is, are you going to transcode or simply stream the media? How many simultaneously? If you can answer those questions, the choices become easy.Good lord rock and a hard place.
I think you just want the most powerful system that you can have for your money. If you are willing to increase the budget you can get more. But I think you need to think from the other end. What hardware (at any price point) will satisfy your current needs and your new requirements for at least the next 4 to 5 years.