Ok well to help you answer some of your questions, You don't want to put a b20 head on your motor, for the reason that that would take away Vtec, which is a bad thing, since you are trying to make a all motor setup.

As far as what it would take for you to get 200-240 all motor, what is your price range? If you have a deep wallet, than a K-series swap would put you in that power range with simple bolt-ons no problem.

But typically bolt ons for a B-series will not put you in the over 200 range, the way you would do this with a B-series would be to build the motor, or at least the head.

Hope this helps at least a little, an by no means am I a expert or anything, so hopefuly someone with more experience can give you some more outlook/advice.

JT