Marc,
I have also sewed the plastic track slugs to a new curtain...twice. I just buy a regular shower stall curtain, cut and seam it to fit the opening (the inboard side has to be a little longer than the outboard side, since the track is fastened to the overhead which has a camber up toward center of the cabin), and then sew the slugs into the top of the new curtain. No big deal if you have a sewing machine, and if you don't, it's pretty straightforward for a friend who has a sewing machine. If the ones available in the above posts don't work out, it's kinda fun to pick your own curtain & modify it to fit.
Dan Morehouse
1981 E-38 "Next Exit"