A friend has some subs that suffered a poor recone job by their previous owner. There are gaps (air leaks) around the surround that I want to seal. It looks easy enough to do from the back, just peeling back the surround and dropping a bead of glue in. The question is what kind of glue do I use, and possibly more important, where can I find it?

The only glues I actually have already are CA-based "super glue", various "goop" products, and 2-part epoxy glues. I want to buy the right glue for the job however if there's something better I can use.

I also need to glue the dustcover, which is peeling off.

just buy a High strenght 30min 2part e-poxy. it'll be a clear color. just mix, add into the gap, clamp. and let dry for at lead 6-12 hours.