Two kerr black holes?

It may well be possible, but it's not been done to my knowledge. The Kerr metric is a vacuum solution, and all its properties come from the spherical symmetry. The symmetry of 2 BHs is not so obvious or helpful.

 

It is specific, but you might want to lookup the double Kerr solution.

Stephani in Exact Solutions of Einstein's Field Equations briefly mentions this in chapter 34.4.

 

For two Schwarzschild black holes, the classic solution is due to Misner. A search for "Misner Inital Data" will pull up plenty of recent papers that might give you a derivation.

For Kerr black holes, check the paper here:
http://arxiv.org/abs/gr-qc/9806017

 

The exact solution describing two Kerr black holes was presented in D. Kramer, G. Neugebauer, "The superposition of two Kerr solutions", Physics Letters A, 75:4, 259-261 (1980). It does not admit an equilibrium state.