If you're doing mini-ITX as opposed to the more-common ATX, it's presumably for a reason. You might want to list a rationale, since it'd help people make suggestions, as there are different reasons someone might want to go down that path.
Like, a while back, I was looking into doing a mini-ITX build because I wanted a machine that I could lug around as a laptop alternative. For that, being small in volume (even relative to typical mini-ITX systems) and durable is important.
A different person might want a cheaper case. Or just to use less desk space.
Any thoughts on keeping it quiet, since this will be next to my TV?
I looked into this a while back. Very quiet builds are kinda restrictive (especially for gaming systems).
You may have luck just putting it in a (ventilated in the rear) cabinet. Maybe stick some sound-absorbent foam on the inside.
Or just move the PC elsewhere, if you can run an HDMI cable to your TV and a USB cable for input devices into the room. You can get (pricy, stiffer) cables with more shielding, or (also pricy) ones with fiber optic cable inside and a transceiver at each end that permit for much-longer-than-normal cable runs, if you can't manage it with regular cables.
