>>320246584
FBT is full body tracking. Don't worry about that until you've got plenty of experience in vr and want to have your complete body language in vrchat or curb stomp people in blade and sorcery.
If you get a vive you can get just the index headset for a visual improvement and it'll work with vive controllers and base stations and you'll save yourself a little bit of money over getting the 1k full kit especially if you then sell on just the vive headset.