It needs to be dacron, and the battens typically fiberglass. Sailrite.com | Home
is a good supplier of both, or Discount Marine and Boat Supplies - Inflatable Sales - Defender
. You can also probably buy what you need right here at sailnet.
That's the fact part, now the opinion. If your sail is that badly beaten putting in new batten pockets won't help because you really need to get it right- battens come in all shapes, strengths etc - and just guess won't get it right. You'll wind up with a baggy sail and poor shape. Battens have a lot of force on them, the idea of one shooting out the sail when you tack should be on your mind.
You are better off cleaning up the torn parts and going batten free. Or buying a new or newer sail in better condition (try searching for used sails online - several places sell them, for example Bacon Sails & Marine Supplies - Discount Sailing & Boating Supplies