[vbezhenar]

I suggest you to look at a 3-5 year old business models from trusted vendors (whoever you like, Dell, HP, etc) and check out their hardware and whether it's compatible with Linux. They usually have good enough build quality and unless there's some incompatible piece of hardware, things are likely to work.

There are mobile workstation lines with awesome hardware (like Xeon, ECC, Quadro) which support Linux officially. If you have extra money to spend, you might want to check them out as well. Every major brand has those. They usually are bulky and not that mobile, but they are powerful.