The 2 ft tall part isn't usually a problem, but that damned jet-noise just doesn't cut it in a media application.
If hard drive noise for quiet drives is a problem, then there is no solution, as SSDs are too expensive for the storage amount a media server needs.
Who said anything about SSDs? Nice try. But do go on...
Otherwise, though, there is nothing that requires a computer to be noisy. My HTPC only makes any noise because it has a video card that is beefy enough to play games. I have a fanless card that would do just as well if I was only playing media, and the processor is the same Core i5 as the base Mac Mini. The power supply has a fan that only runs when it gets too hot, but it never will as the parts in the machine can't ever draw enough power.
You mention that your "HTPC only makes noise because..."
Who cares WHY it makes noise. It makes noise. Next...
The HTPC case is brushed aluminun with a standard media rack size,
Whatever a "media rack" is. The Mac mini is brushed aluminum, too. So?
and can hold two 3.5" drives and two 2.5" drives internally, which could easily be 10TB (the 2.5" drives don't have height limits, so I can use the Western Digital 2TB drives). This looks far better than a Mac Mini with 2-3 external drives connected to it.
So, you're going to do backups to the same box as your media library? I hope you realize that you are one Power Supply failure from losing your entire collection, and that a RAID (if you are silly enough to put your trust in consumer-level RAID) is no substitute for backups... So, since I ASSUME you aren't that stupid, exactly HOW do you avoid having "external drives", whether directly attached, or somewhere else?
Also, those 2TB 2.5" WD drives are $189 apiece; so you have 2 HARD DRIVES that are 2/3 of the cost of an entire base-model Mac mini. Yeah, sounds like a great deal you have going there...
The best solution is a storage server in a different room, and then you can use anything for a media player..
No, all you need then is ????ft long HDMI and/or RCA cables, and a perfectly-positioned "other room". A lot of people don't have that luxury.
.you don't need a full-fleged computer like the Mini. I've got sub-$100 media players that can play back pretty much anything, and they have no moving parts, so are completely silent, and draw less than 30W from the wall plug.
Oh, you mean like an AppleTV, right? Yeah, you can have one of those, too, for the other TV. And then you know what? Because of how AirPlay works, you can then essentially have TWO "HTPC"s.
Oh, and I note that you DIDN'T crow about how your HTPC was "so much cheaper" than a Mac mini. Telling,