--Video Card - I strongly recommend Nvidia. I realize that's more challenging in a laptop, but their drivers and support are much better.
--Wireless Capability - Personally, I PCMCIA wireless over built-in, but in any case make sure the wireless chipset is well supported. I use a proxim card which worked with next to no effort.
--Sound Card - While I seriously doubt you could find a laptop sound card that isn't supported, it's still worth a look. Nothing makes me frown faster than a lack of tunes.
--Network Card - Well, maybe no network access could make me frown faster. Linux supports a large variety of NICs, but be on the lookout for Broadcom based cards. If it's a 3com, Intel, or Realtek chipset, you're almost certainly a winner.
If you make good decisions on those, your shiny new laptop should work very well. As far as dual-booting goes, I just have one major caution: install Windows first. Why? Because many Linux partitioning programs pay no attention to cylinder boundaries. Windows will then freak out and "fix" the error by moving your partitions to the nearest boundary. Fixing this is not fun.
My sister opened a computer store in Hawaii. She sells C shells down by the seashore.