If you haven't already, you can read my reply in the "desktop vs laptop" thread:
http://www.twcenter.net/forums/showp...18&postcount=6
But basically, if you spend a great part of the year camping and plan on buying a powerful laptop, make sure you have something to plug it into, otherwise it will become pretty useless (due to automatic under clocking on battery) and it will run out of juice on battery quite fast.
Personally I wouldn't go with alienware in either case. At least some months back, when I was in the laptop market, DEll had some nice deals on their high end models (and they own alienware now), you could also buy coupons on ebay for even better prices. Other than that, you should also check out Sager's high end models as well. They have great quality, I hear, and a lot of power for a good price.
If you are seriously considering any particular model, I would suggest checking out NotebookForums.com or Notebookreview.com and read complete reviews, as well as threads on the model to see what kind of possible problems people experience with them, and other things that you might not find out about until some time after you've bought your laptop...
good luck