tbessie --Wow, that's a lot of expense for a relatively undemanding role for a PC these days. Aside from fast bootup, an SSD really doesn't provide any improvement in HTPC performance (at least for me). I'm surprised you find the HDD noise so bothersome. What are your environmental conditions? ie -- where is the HTPC, where do you sit, ambient noise, etc. I have a PVR from Telus (phone/internet/TV) that sits under the TV, and it sets the noise floor of my TV room. Its HDD & fan are considerably louder than any noise my HTPC makes beside it, but both are 7-8' away so with the TV on w/ any program, the noise is completely masked. Mind you, the only time I am in that room is to watch something on the TV.
A WD 4TB Red is pretty much inaudible esp. if you control the vibration transfer into the cabinet the PC sits in. (Soft rubber feet, whatever.) I have a 120gb mSATA SSD + 1TB 2.5" 5400 HDD in mine (a NUC), but 99% of the program material is in a home server downstairs, accessed w/o issues over gigabit LAN in XBMC/win7.
I have very little space in my apartment for a home entertainment area, so I have a vertical equipment cabinet with the TV on top, integrated amp below that, and HTPC below that. I've positioned two medium-sized speakers on pedestals behind that. All very cramped, but works.
My couch is RIGHT next to this, so my head is about 8 feet from the cabinet/TV while watching. Ambient noise is pretty minimal, except for the refrigerator motor turning on in the kitchen, or someone having a party next door.
With nothing else on, I used to very clearly hear the noise from my previous HTPC build. A lot of it was the smaller fans in it (rear exhaust were 60mm - pretty tiny and noisy, despite my having put in the quietest fans I could find. The CPU cooler was also a bit louder than it should be, and I could also hear the hard drive spinning (WD Green 3TB model, I think).
The new setup has a lot of 120mm fans running in it - probably more than I need. I can't hear it on the couch, though, and when I put my head near it, it produces a low-pitched whooshing. I could probably disable 2 of the fans and make it quieter.
But yeah, this was overkill - as mentioned elsewhere, I'm using a Z97 board with 32gb and an overclockable 2nd generation Haswell i5. Much much more than I need, but at least I know that this computer should last me many years and handle any upgrades in software that may be thrown at it. I could have still run the old one (which had an i3 in it and 16gb of ram), but it's oh-so-fun to upgrade sometimes. Like a kid in a candy store.
Sadly, there is no other place I can put offline storage, except perhaps in a storage room off the kitchen, but that's already too filled with stuff (and would have to be accessed via wifi). I often leave the HTPC on at night as it hosts my audio streaming server. I used to walk in during the night and hear it humming along; now I can't hear anything when I come into the room, and I like that.
Even so, the integrated amp I'm using has a couple of 60mm fans in it that are pretty loud, so any sound reduction I've got in the PC is canceled out by that; though it's only on when I'm watching a program or listening to music, so I don't hear it then.