What one hopes to get is hardware compatibility and technical support. What one
gets in reality is anybody's guess. This is new territory for many OEMs and
consumers. Budget computers can have older technology and lower quality parts.
It is buyer beware. It may come down to whether you can count on the dealer to
give the support that you may need.

Building your own computer will require some research on your part. Find out
what equipment works well with Linux and build it into the computer. If you stay
with generic names you have a greater chance for success. The biggest problem
for Linux developers is the failure of equipment manufacturers to release
information on proprietary equipment. The biggest offenders of this are laptops,
wireless cards and some webcams. ATI is routinely uncooperative but some people
have good success with them. The key is to research.

Check out: http://www.linux-drivers.org/