Worth mentioning...
Virtual PC, packaged as Windows XP Mode in certain copies of Windows 7 does not support Direct3D. It should only be considered for very old games since any game that requires 3D acceleration will run in software mode. Some older titles may still run well since modern CPUs are considerably faster.
Virtual PC was not designed for gaming, so that's something to keep in mind if you truly need XP to run a game.
LoL - OK, forget everything I said (I never tried direct 3D, because every game I owned worked under Win 7 anyway).
I still think most games (including those you mentioned) should work under Win-7 compatability mode. Also, if you really can't find an XP laptop, and you don't need your old one anymore, you can use the product key from your old one on your new one (technically you shouldn't if it's an OEM licence, but I've migrated OEM XP licences before without issue). You'll need access to an XP installer DVD if you do it that way - most laptops come preloaded and don't include the DVD.
