Here is the build for my HTPC / NAS

Intel Celeron G530
ASUS PH877-1 1155 INTEL H77 - Mini ITX board - 6.7" x 6.7"
6GB RAM
PicoPSU 120w-25v

VMware hypervisor and VM's go on dedicated OS drive - Seagate Momentus XT 500GB 7200 RPM 32MB 2.5" Sata 3.0Gb/s On Sale for $55 until 11/21 at newegg

For NAS drives:

3-4 high capacity 3.5" hdds

Ultimately, it would be nice to have a couple of cut outs in the front for USB plugins. There is no optical drive in this build. Would love to keep the box as small as possible, still unsure about heatsinks for G530 so that needs to be accounted for.

Thoughts?

Thanks ladies and gents!

Ordered by Size:
CFI-A7879: ITX case with 4 bay hot-swap 3.5".
Chenbro ES34069: ITX case with 4 bay hot-swap 3.5", comes with a pico PSU in 120w or 180W.
Fractal Design Node 304: ITX case with room for 6 3.5" drives
Lian Li Q18: ITX case with 4 bay hot-swap 3.5", aluminum case with room for an atx PSU (or a large CPU cooler and Pico PSU, fits one 5,25" drive.
Lian Li Q25: ITX case with 5 bay hot-swap 3.5", aluminum case with room for an atx PSU (or a large CPU cooler and Pico PSU, same size as Q18.
BitFenix Prodigy: ITX case with room for 5 3.5" drives, one 5.25" optical, standard ATX PSU (140mm depths recommended), 4 2.5" drives, a big CPU cooler and a big graphic card. Big for an ITX case.

Boost,

That's a great list, thanks so much for the feedback!

CPU: over here the G540 can be found cheaper than the G530, check prices. (probably supply/demand)
Mobo: H77 good chipset choice, but that Asus mobo doesn't include a decent Fan Xpert version (+ or 2). If you want software fan control, I'd check sister models or Gigabyte.
RAM: get 8 GB (2x4 GB). Not only is it affordable, but your CPU's memory controller is dual-channel. 6 GB (3x2) would not work properly.
Cooler: 65 W TDP on CPU so you can get just about any decent cooler, including compact ones. I recently helped assemble an HTPC build with the Scythe Samurai, but it blocked the PCI-E slot on a mini-ITX mobo and one of the screws broke with no spare in the package, so buyer beware. I would go Noctua for peace of mind, check out the most recent SPCR review!

WD Red is probably the best storage HDD at the moment for performance and silence. Only obstacle would be the budget, as they are currently a bit on the expensive side.

Of the list so far I personally like Fractal Design cases the best. Have been solid all around. Silverstone makes interesting HTPC cases that are living-room presentable, the Grandia series has some with hot-swap drive bays.

On the RAM point I agree with going 2x4Gb RAM. 3x2Gb or 4+2Gb will work and the BIOS may SAY 'dual channel enabled' but only in an asyncyronous mode which is slow. I did some benchmarks some time ago adding a spare stick of RAM and performance does get worse in such circumstances. You'd be better off with 2x2Gb for many tasks than 3x2Gb.

Newegg has the G540 and G530 priced within a dollar of each other at 49/48. I wonder what the increased .1 mhz adds for heat + power as this box is primarily just to serve music/videos off of NAS other files just sit there for backups sake. Is the additional heat/power offset by increment in speed?

I arrived at mobo choice through Newegg filters of 4+ SATA connections, HDMI, and LGA 1155 which left me with a pretty small selection of mobo's to choose from. I like the idea of being able to reduce fan speeds significantly. Any specific recommendations on mobo's given 4+ sata connections and Mini-ITX? This box will sit under TV so it is a living room box.

G540. Why pay the same money for junior models. The heat output increase will hardly be noticeable at this level of efficiency.

No mini-ITX board (Asus, Gigabyte, MSI or ASRock) seems to have good fan control yet, so it's Speedfan or crap control for now. Gigabyte even has you do math to work their manual mode.

The Node 304 can run the integrated (good Fractal Design) fans at 12v, 7v or 5v. I doubt you need fan a fan control beyond that. If you buy a big tower cooler (Scythe Ninja or Thermalright Hr-02 Macho) you won't need any more than the integrated fans (not even an additional CPU fan). That's probably the most silent solution from the list.
You can use a standard ATX PSU in that case with a tower cooler. The Seasonic G360 is inexpensive and quiet (no cable management in a tight case, though), but for the best power efficiency you should stick with a Pico PSU.

+1
Power increase will be more likely fractions of a watt than 1w or 2w.