Copy content of one node into different content type
You may be interested in Node Convert module:


  Node Convert adds a menu tab "Convert" on the node view page, i.e. node/1/convert, which gives the ability to convert the node from its current node type to another node type. The module provides the means to transfer all the field values of the current node type into fields on the destination node type, or discard them.


Of course this does not clone, but you can use node clone to create a clone of the A content type, and then convert said clone to content type B.