Bane isn't Batman's equal mentally...
It's not so hard to weaken someone by giving them countless tasks to do, setting them up for you to take them out yourself... when they don't know you exist. It's simplistic plan that doesn't need THAT much intelligence to implement.
Let's not act like prep-time for Bane is somehow equally useful as it is to a Batman, or a Mr Fantastic or The Majestic or someone... He once had a simple plan which he implemented very well. That's all.
Read more Bane stories than
Knightfall before making the assessment that Bane can't rival Batman intellectually *cough*
BaneoftheDemon*cough*
That being said, Venom still wins this easily.
Venom (the drug) doesn't make its users that much stronger than they already are. We're talking
very low level super human strength here, so it's not going to give even a slight advantage to Bane against Brock. Heck, I'll even go as far to say that it'll be a
disadvantage with the strong possibility of clouding his judgement (one of the reasons why he was smart enough to kick the addiction after one storyarc when it served as his achilles heal plot device) as well as providing a highly exploitable weakness for Eddie to use against him.
As for prep time, Bane has plenty of experience with all sorts of weapons but he's more like a guerrilla fighter (grenades, machine guns, mines, etc) and even with prep time he simply wouldn't have access to the kind of firearms that could possibly give him any sort of edge here (like sonic weapons or a disintegrator ray). Even if he did, like Anubis said, that would only get him so far with an opponent that can move with strength, reflexes, and agility far beyond a normal human.