You don't need any cable or digital subscriptions at all - it is a one-time payment to watch the fight. Payment is made with CC, PayPal or through iTunes / Google Play, Roku or Amazon. Your purchase will include the show in 1080p or 720p HD + SD and a 96-hour replay.
The show will be linked to your account and you can watch on any device with FITE installed if you are logged in. (only one device can stream at a time)