Better quote your budget in US$ or euros.
I think it is generally agreed that Intel win the power race on cpus, but amd are a sensible price.
I think the quality of software support for your chips ought to be a prime factor in your decisions.
What you can get parts for also matters. A developer I know was very pleasantly surprised by the OLPC laptops, because it used what it had well.
The sort of thing I would think through is that if you're bundled a crappy video card in a laptop, you can't change it. You can see issues on the HCL here or www.linux-laptop.net