Although I love my b series, I will have to agree that K series is superior. In the November 2003 issue of honda tuning Hytech Exhaust's RSX-S was putting 261.9hp and 170 lb-ft of torque to the wheels all motor, and that was still having good driveability (according to Honda Tuning). And the motor didn't really have all that many power adders. Here is the parts list:
wiseco pistons, billet connecting rods, ported head, stainless vavles, titanium retainers, indy car springs, custom intake manifold, hytech stainless-steel header, 3-inch exhaust, hondata ecu, mugen limited slip, and ACT clutch
Not sure if that is the complete parts list but that is all they listed. The most that I have ever seen out of an all motor b series is 268 at the wheels, and that was a full race motor that revved to 11,000 rpm. There may be a more powerful b series; I just haven't seen it.