Daniel,
I truly don't understand your market that well and do not know how things work...I'm hoping someone else will jump in here and help out.
But I would imagine your looking for a Company or B2B type of deal.
For myself, I am able to go straight to the manufacture for a majority of my products as they come off the line all ready to go (manufacturer example). As for custom products that I will assemble, I am usually able to order all of the parts needed from ONE Company that distributes everything (company example).
I just searched...
Computers>Wholesale/Distributors>China
Decent amount of results.
Found?
http://tclhk.en.alibaba.com/ -- seems they distribute whole PC's, Laptops, etc.
Now this may not be exactly what you wanted, but it?s a start.
I also found many companies that distribute the individual parts for the computer - the monitors, hard drives, etc.
Hope this helps...!
Sam Burnette