advantages of branded computers
I agree with everyone saying "don't do it".
I used to work as an engineer for one of the top US computer makers. Most people have no idea how much testing the big computer makes put into integrating their systems.
Say we wanted to support shipping 3 different sizes memory sticks from 2 different vendors. We would test every possible permutation of size and vendor in loading the memory slots. The test systems were run in an environmental chamber where we ramped the temperature from the minimum to the maximum operating ranges. We also ramped the power supply from -10% to +10% of specification.
Say one of the disk drive vendors wanted us to qualify a new capacity disk drive. That too took a similar amount of testing; racks full of computers reading and writing to the disks while in the environmental chamber.
This testing *did* uncover problems frequently. We would discover that (for example) we couldn't use a certain Hitachi memory stick with a certain Samsung memory stick if the temperature rose past a certain point. We would find that a specific Western Digital drive had errors under certain conditions with a LSI controller but no problems with an Adaptec controller.
The point of all this is that there is just no way that a small shop is going to have the resources that a major computer maker does to test their integration. There is more to successful system integration then just grabbing a bunch of off-the-shelf components.