Yeah, they are expensive your right, as it is the latest technology.
The 5600 I don't know much about, though it is one range below the 6600, and so would run them, but not with advanced settings. It's in the same sort of league as the Geforce 5200, but a bit faster seeing as its built on the same model. So would have Direct X-9 for new games. Though to hold the test of time, and for games that will come out, I wouldn't recommend it.
Yeah the 9000 will be below the 9700 and 9600 and even lower, so this isn't the choice either for new games, as it is in the same league as the Geforce 4 MX series, and so not a Direct X-9 card (to push new shaders for new games) but a Direct 8.1 card, though will run newish games, but at very low settings/resolutions, and so also not recommeded for a laptop user.
The x600 will run new games as it is a Direct X-9 card. I have a radeon 9800 Pro card and it gets okay speeds at high settings at the moment, and this card is past that, and past the X300 that came out after that. It is a model below the X700 which is as good as a Geforce 6600, though I wouldn't know the model the X600 would be to, though shouldn't be too bad
The AMD 64 processor is a very good processor for gaming, as any AMD processor is. It'll also future proof you as it has a new technology (64 bit instead of 32 bit which applications use at the moment) so when new applications come out, it'll take full use of them.
Pentium 4 Processors are better for multi-tasking though, especially since they have HT technology (Hyper Threading, higher bandwidth memory) if you are into running loads of software/video apps.
Though Athlon 64 is more future proofed and can be better for games to get minor improvments in frames per second, but isn't worse in any way than a Pentium 4 in terms of quality
A Pentium M is a new processor, and is just a low power version of the Pentium 4 processor and is just used for Laptop users for battery reasons, and so isn't bad, and will run new games as long as you have a good video card to go with it like anything you buy.
Though if you can get one faster than 1.7 then of course you'll get more speed for other tasks you might want to use, and so would feature proof you more
One thing I have to say about Athlons now though:
If it has a model number of 3500+ for example, it means that it is running at 2.2GHZ (They are more efficent that Pentiums, and the GHZ rating is very misleading as it doesn't always mean a better processor), because Athlon has an other way of saying it, and the model number means it'll just be as good as a Pentium 4 3.5GHZ processor and a bit better at some things, even though it is running at 2.2GHZ.
In pentiums though, the old rule applies
Because its a laptop and can't be updated very easily. You should seriously think about spending a bit more
You won't be dissapointed with the results if you do, especially if it lasts a long time, huh?