This web page
http://www.craitontesting.com/ says:
"Microsoft will accept your Designed for Windows Media Center
Edition Logo submissions starting September 15, 2004."
If that is true, it is too soon to see products with the Logo.
If you visit the Microsoft web site, they don't even mention
motherboards as being candidates for the Logo! Maybe an ordinary
Windows logo is good enough ?
Your problem is, you are trying to use motherboards with
integrated graphics, and the feature sets on those leave a lot
to be desired (every motherboard works slightly different in
terms of video modes supported). Perhaps installing a video card
with the Logo will help. That way, there is one less feature
required of the motherboard.
Why not email Microsoft and ask them how best to guarantee MCE
will work on the computers you build ?
Paul