An AppleTV, a Mac Mini HTPC - or both?

We love our AppleTV. It's tiny, it needs only 2 cables (HDMI and power), and it can access the entire iTunes content ecosystem. 

We've used it to rent movies, stream almost everything from our iPad, and play music from our full iTunes library - which is stored on our iMac, while using an iPhone as a remote. 

Clearly, for a "hobby" device, Apple has created a killer iPad accessory. It's practically mandatory at this point. Go get one.

But you know what it can't do well? Stream a video library. Which is why I'm interested in an HTPC.

I know, I could jailbreak a 2nd generation AppleTV, and load the ATV version of Plex, and then I could use my AppleTV as a light-HTPC. I could. But I'm not going to. I want something more powerful - a fully fledged HTPC. 

And an AppleTV, too. 

There are really two aspects to the system I'm envisioning - I want a small, sleek HTPC box that's attached to my home theater system, and I want massive, massive amounts of storage, on a NAS that's somewhere hidden away. 

Ideally, that NAS will be able to provide HD video to the HTPC over wi-fi.... but if a CAT-6 connection is required, so be it. I'm going to be running wires all through the basement ceiling during that renovation, so it probably wouldn't be a big deal to send a couple ethernet wires into the living room. 

For the HTPC itself, I'm really only considering a Mac Mini. There are other HTPC cases on the market, but none of them have exactly the "Apple" style I'm looking for - a tiny, featureless, almost completely silent aluminum box, remote controllable, with an HDMI out. 

For the NAS - well, style is less important. I'm envisioning something very "IT-systems looking", squatting in the basement - a big square black-mesh enclosure with LEDs all over it and about 6 drive bays. I want redundant backup storage for all of our music and family photos - and I want to be able to dial up Season 1 of DuckTales for my kid on the HTPC, and then the first six seasons of the Simpsons. 

I'd like to relocate the entire iTunes library to the NAS - but from what I've read on the internet, this can be a difficult effort, with little to be gained. So for now, the AppleTV remains the gateway to the iTunes library.

XBMC menus, showing "The Dark Knight"

Plex Media Server menus, showing "Arrested Development Season 2"

I'm guessing that Plex or XBMC will be our HTPC media server front-end. Both of them are beautiful. Both could do the job. Some more research is needed on my part on which direction to go - regardless, I'll be downloading this kind of art for all menus. 

This is pretty exciting stuff. And yes, it's probably overkill to leave an AppleTV in a system that ALSO features an HTPC - as I get more familiar with the HTPC's capabilities, there's a solid chance their functions will overlap. But at least at the outset, they will be doing different things - the ATV handles AirPlay, while the HTPC acts as a video libary.