Mara Jade isn't nearly cool enough to head a title with Batman, who again is only once at best [The Dark Knight Returns] portrayed in a manner that suggests he could be a fair fight for her anyway.
That said, if people like the premise, I'd be fine with Mara Jade circa LOTF and TDKR Batman.
I'm particular about this incarnation of the character because he strikes a reasonable balance between the weaker depictions [live-action] and the absurdly dangerous continuity and animated versions. No one in the former category - particularly the Nolan/Bale Batman - has demonstrated on any level the ability to prepare for and deal with a prescient psychokinetic who can dodge bullets and cut a tank in half.
A continuity or animated Batman lies on the other end of the spectrum. IIRC, in JLA: Tower of Babel, Batman's notes explain that if he was violently confronted by any rogue charter member of the Justice League barring Superman, he'd be able to "wing it." He prepares contingency plans anyway, but the fact that he feels he could handle Wally West or the Martian Manhunter on a whim suggests that a fight with Mara Jade would be a walk in the park. Physically, he often does difficultridiculousimpossible things.
In a JL[U?] episode, TAS Batman rewrote a program for a belt that controlled time, and managed to do so simply because "he got a good look" while fighting the man wearing it. That establishes his ability to deal with extremely weird shit in a very short period of time. If you want to see what he can do physically, just YouTube it.
TDKR Batman is still fast enough to - mostly - evade gunfire, agile enough to shoot a tightrope across rooftops and sprint over it, strong enough to pull a man through a sheetrock wall, skilled enough to do lots of extremely skillful things, and smart enough to qualify as the goddamn Batman.
This Batman, however, is fallible. He is weaker, slower, and yet apparently much luckier than he was in his prime, when he could presumably ban gay marriage with a sidekick. He is technologically far behind his continuity and animated peers, which is not to say that he doesn't have a tank impervious to all human weaponry, a helicopter that can turn invisible, and a power suit that - with lots and lots and lots of preparation and a wee bit of atomic luck - helps him beat down Superman, but he's more limited in what he can bring in against Mara.
So I vote Batman as seen in The Dark Knight Returns. I think this is the one instance in which a case could be made for either character, depending on what parameters we establish regarding the nature of their preparation.