i need to know if Intels SSD or Crucials garbage collection is better and which one to use with Windows XP?
If it is for a single SSD setup I would go with the Intel SSD because they have better support, updates, and utilities like Intel SSD Toolbox that will make your life much easier. Also, because it is so popular there is an abundance of information found on various forums and websites from previous owners, which when you're having issues is a huge blessing.
If you were going to purchase 2 SSDs and Raid them together I would recommend crucial. This is because the TRIM command cannot currently be passed through Raid controllers. Garbage collection will help alieveate some of the negative effects you would encounter from having TRIM disabled.
Regardless of which one you choose, I would highly recommend switching over to Windows 7 if it is an option for you because of the native ssd and trim support unique to windows 7.