Just to mention a few things about the PICO PSU...
You limit yourself by only purchasing a low rating PICO. I own a 90W PICO PSU, because the system that I use that with will max at 60W with two drives running actively in it. I don't need anywhere near that kind of power if I run a single laptop hard drive.
I would suggest looking at Wide Input models of the PICO power supplies, because it will give you an option to run much more efficiently, as well as power higher wattage parts at the same time. Unless my memory is totally off, PICO power supplies should be available all the way up to 220W, if not a little more, so if you were to get a good 16v power brick at around 13A, you'd be just shy of maxing out your PICO. Use some lower wattage components, and you could in theory power a lower end quad core machine, with a mid-range graphics card, all off your PICO. That doesn't even get into what components to specifically use, but there are plenty of options. Low profile is your friend if you're looking for power savings. All the way down to the RAM and hard drive, but you need to define the line where lower power needs to be given up for some form of performance.
The second you start going into video capture and encoding however, that's where you're going to need to make sacrifices of low power for performance. If you were to go with say, an ITX motherboard that's socket 775, some low profile memory, and say, a low end Pentium Dual Core, you could easily idle below 50W, but I'm confused as to what you're really looking for in terms of information. Determine the wattage of video cards, and determine the wattage of the motherboard you want, and add the two together for the answer you're looking for.
Alternatively, I would say you should use software utilities that allow you to downclock your hardware when you know you're not using it. Drop your CPU down to 1.0GHz or lower, drop the GPU way down as well, that's what will make a difference for you. Counting on stock hardware to sit exactly where you want it to is not going to get you the result you're looking for, and you're going to need to "get your hands dirty" so to speak, in order to get the results that you really want.
Regardless, you're going to need either an 80+ or higher power supply to get anywhere close to the numbers you want, and it would be even better to use a PICO in order to save those extra couple, as well as remove heat from the case.
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A 9500GT with 1GB of RAM is the most pointless thing since NASCAR.