Carnage was cool, but you can't do Carnage without doing Venom first, that would seem out of order, and by the way, you should read the Rogue's Gallery in the Spider Man DVD, Dis.
Sandman is some guy who got in a freak accident (big surprise) and now has the powers to morph into sand, or form himself into sand sculpture of weapons, like I think he turned his arm into a a mace/club with long needly spikes once, it was all beige and sandy though. And maybe Hob Goblin will make a cameo, but then it would mess up the story, because Hob Goblin was like a Green Goblin Enthusiast. I guess Green Goblin's son is an enthusiast though... hm...