Who told you a B20 is weak? Yes it might not have the most well designed sleeves but it is by far one of the better torque producing honda engines.

B20 is a great platform to start from but will require more work and money than the other B-series engine. But any of the B-series engine will work fine in that car dont get the b20A its from the stupid early generation preludes. B20B and B20Z are the CRV ones--both engines are awesome. It really depends on what you want really. H22 will haul a$$ as well. H22 is a great engine to go with but will require some fabrication work and not as the B series just because its a tad bigger.