smoothdrag.com
Dawn has got everything you need, including Stella.
I replace all my drags with carbontex, EXCEPT Stella, as I've never damaged a factory stella drag. Above statement is correct on the '13 stella.
just got done doing a few stradics, $8 per kit.
Be sure and get a jar of Cal's drag grease to lube them up.
Shimano drag grease is good, too but a little messier to apply.
forgot- is it worth it? Yes. huge improvement over felt and too much grease.
usually will require a little more preload to get the drag #'s you want, but is much better and smoother starting, no more jerky drag!