Re: Help me choose my new laptop !
I don't think the brand really matters as long as the main components of the computer are compatible with Linux. Try and get as much info (specs) on the computers you're interested in and google the names of the components therein to check for possible Linux issues.
That's how I would do it anyway if I were in your place.
Desktop : iMac 21.5" (2011) Core i5 Sandy Bridge - AMD Radeon HD 6750M - 8Gb RAM - OS X 10.8.3 Mountain Lion
Laptop : EasyNote TS 44HR (2012) - Core i3 Sandy Bridge - Intel HD3000 - 4Gb RAM - elementary OS 0.2 + Windows 7 Home Premium SP1