Wordpress - Vbulletin Integration

I am looking to integrate wordpress with an existing vbulletin forum. I wish to keep all vbulletin members and make them members of wordpress and from that point forward keep all members in sync. Also it would be very handy that if logging into one it also logged you into the other. This would keep things easier froma users perspective. Existing Vbulletin Wordpress bridges have been tried and none of them mapped the user base over for me. including one whoses state purpose was to map the user base. It also would be desire-able that deleting a user in one system deletes in another and if a user changes his password or email in 1 system that the change is reflected in the other system. I would prefer that a change in either system pushed the changes over to the other system but im quite happy to edit templates to remove password and email changing from one system if it means that code for the other system handles it all.