We use something called Superdeck near the beach areas. This stuff just lasts forever. I can’t seem to find it online. It’s sort of grayish.
You’re probably thinking of Deck Mate screws (Phillips Fastener Products, Inc) I’m getting ready to build a deck in my back yard today and happen to have a box in front of me.
I’ve also used square drive screws in the past and I love 'em. Just buy a couple extra bits and you’re golden.
As to the OP; I will probably use Outdoor Wood for the decking (I only have material for the sub-structure so far) 'cause Trex costs >3x as much in this area and The last deck I built using Outdoor Wood is still in great shape.