If I was regripping a polyester board I would for sure use the surfboard resin as it is much cheaper $10 vs $30 or something, it's just I've been regripping epoxy boards (stickered and some plastic skinned). Harder- now that they are including the wax is it as hard? Either way both resins will last as long or longer than stock grips.
lookkc- I like the International Intergrip non skid aggregate, when I first started doing boards chandlery suggested glass beads... all beads are too harsh (I know i've got 2 different grades I cant do anything with- one day I might treat some stairs or something). With the International stuff you can load it up if you want coarse etc, pepper shaker works perfect for this.
The resin is from these guys-
boatcraft.com.au/informationpages/productoverview.htm They are based at Loganholme and were very helpful (and their general epoxy price seemed quite reasonable).