I recently statted Bruce Wayne for d20 Modern (just the core book). A Justice-League-type Batman would be at least 20th level (the JL is epic by definition). In the Animated Series, you can tone him down a bit. In this build, he'd be a Smart/Dedicated/Fast/Martial Artist.
For D&D, I'd say Batman is a Rogue/Urban Ranger. I'd trade Animal Companion for a Cohort (sidekick), Wild Empathy, Spells and other nature-oriented abilities for Bonus Feats. Combat Style would be Weapon Finesse (Unarmed) at 2nd, Weapon Specialization (Unarmed) at 6th and Improved Critical (Unarmed) at 11th. I'd also trade some abilities for Savant Lore (like Bardic Lore, but focused on academic stuff).
For stats, he'd be Str 17 (there ARE stronger mooks than Batman), Dex 18 (I'd put Nightwing at 20), Con 16, Int 22 (starts at 18 and gets bumped up with levels), Wis 18, Cha 16 (that's just too twinky!).
His 18 Int and rogue-level skills would put him up the wazoo in skill points (48 at 1st level!). SO he'd have max ranks in Intimidate, Gather Information, Hide, Move Silently, Balance, Tumble, Climb, Jump, Disguise and Bluff.
His feats would go along the lines of Improved Feint, Combat Expertise, Improved Trip, Improved Grapple, Alertness, Stealthy...
The bat-suit would be equivalent to a non-magical Light Fortification Shadow Studded Leather armor that gave the user a +5 bonus to Intimidate checks.