Unless the Sinister Six can get their hands one some sort of sonic device, I don't see them winning. The symbiotes have all of Spider-Man's abilities to an even greater extent. The six get beat by Spider-Man all the time; a team of spidermen on steroids would destroy the Sinister Six.
Yes, of course it's understandable. He's Batman! If he didn't prepare for things like these, then he'd just be some guy in a batsuit. It's in his character to prepare for things. Batman has no powers, so he must maintain an edge or advantage against the giants that surround him somehow.
I'm gonna go with Superior Spiderman because he is much cooler than Miles (of course that's just my humble opinion) and he has the mind of Dr Otto Octavius in control of Spider-Man's body. You must admit that is a pretty awesome combination.