Laptop System equirements for SW

First, figure out how much you want to spend.. then go from there..
You would be better off with a newer arch processor (the i# family) or at least the core 2 duo/quads at the highest clock speed you can afford, A decent amount of ram (max the bitch out) and a decent video card..

It's not going to be just the OS that's the gotcha, it's the graphics chipset. There is no laptop out there that will let you swap graphics chips, what you get is what you're going to use, or not. So shop to see what's in there for graphics and what the software wants. Then buy. Chances are you're going to be 3/4 of the way to the grand mark or more, nVidia and ATI chips in laptops are put into the higher-end ones. If it were a desktop, you could probably assemble one for a lot less than that. Upside is that the higher-end laptops are more likely to be running 64-bit OS versions. Low-end laptops have integrated graphics using system memory, usually Intel chipsets do that. Multi- core processors will definitely put you over a grand.
Stan

As others have said...your budget is the driving factor. I can see support for XP is not going to be around in a couple of years...I would of never guessed a few years ago how fast things are migrating to 64bit OS's. Go with the Pro version of windows 7....from what I gather its missing some of the eye candy that you would likely disable anyway. (for performance reasons)