It took me a while going through the eclipse website looking for a 64 bit version of eclipse for windows. The x64 packages location is not that obvious and I only found it after some googling. These two blogs (1 2) pointed me in the right direction.
Later on I found YOXOS, a download service for eclipse. With their web application, downloading x64 eclipse IDE for windows is a breeze, plus you get the added bonus of customizing it by adding components before downloading. It is really good for downloading a one packaged eclipse with all the add-ons you require so and not having to deal with update sites and so on.
Remember, you need to have a 64 bit Java installation to run the IDE. Get that from Sun’s Java download page.