Or find a friend who is willing to zip/rar up his ffxi folder and transfer it to your pc (ie on a lan, or internet if he/she has a somewhat decent connection). Currently it comes down to about 8-9GB I believe.
After that there are a number of ways to generate the needed registry keys, and dll's registered to get ffxi detected by PoL. (PoL itself you can download from playonline.com , they have one up there for the vista comptability, but it works fine on XP). The advantage to this is you'll be skipping the whole patching process (except for 1 file check) as your friends ffxi folders will already be up to date.
I've done the above method without problems to my laptop and back, between xp, vista and vista64.