Sony shouldn't charge you a dime to download drivers. Are you sure that you looked in the right spot? http://esupport.sony.com/US/perl/select-system.pl?DIRECTOR=DRIVER
If you cannot find the proper XP drivers and you want to ditch Vista, you might be better off going to Windows 7. The drivers are readily available and in many opinions, W7 is better than Vista. If your laptop can run Vista, it can run 7. If you bought the computer during the time when MS was offering free upgrades, it will be worth it.