Your “two-way” replication is also know as “bi-directional”
I can recommend looking at two products:
IBM’s Change Data Capture <a href=”http://www-01.ibm.com/software/data/infosphere/change-data-capture/”> -here</a>
and Vision Solutions Replicate 1 <a href=”http://www.visionsolutions.com/Products/Systems-Data-Management-replicate1.aspx”> here</a>.
I know they both support bi-directional transfers. I can’t answer the rest of your questions.