The best online place to buy Linux server

What is the best online place to buy Linux server, and what the best server brand?

a "linux server" is nothing more than an IBM compatible PC with Linux running as it's operating system.
Linux nowadays has drivers for most common hardware on the market, so as long as you stick with industry standard components (ASUS or INTEL motherboards, 3-com or d-link Ethernet, ATI or Matrox video, Creative labs sound card....you get the idea) You'll be fine. I just suggest you purchase the systems from a store that will pre-load the linux onto the units to your specifications so that if there are any issues, they can be solved before the unit is shipped.