Whoa, I had to double-check the date on the OP as it read like a post from 3 years ago. X2 250E?
Is there really a point to building a mini-ITX system yourself and not just going for an OEM build that will likely be even smaller? When you factor in the cost of the Windows license you'll probably end up spending more. When you want small, quiet, and not a huge emphasis on graphics, this is where OEM's shine.
Now granted, this is Can $ and a boxing-after-week special, but this is not out the ordinary for systems of this size:
That's $349 for a quad-core AMD 3600 that will have better graphics performance that potentially even a 440 (not sure, but definitely more than a 210), 4GB, TB HD - and still have a 16X and 1X PCI-e slots. You can fit a low-profile video card in there if you felt the need to upgrade in the future as well. From my experience with these systems that are for all intents and purposes, silent up until the point you place your head against the side of the case and you can hear the fan whirr. And that's all you have, is the CPU and (tiny) PSU fan.
Seems to make a lot more sense to me that cobbling together a mini-ITX system out of oudated components. Price up the motherboard/CPU/case/HD/mouse/keyboard/Windows license, even with a gimped GPU you'll have trouble getting it for under $300.
Buy an OEM, clean the crapware off it - give it to gf.