Workflow Deadline Monitoring and Escalation

Hi,

Here is my scenario.

1. I have a workflow that goes to Person A. If after 24 hours of time Person A has not completed the workflow step then I want Person A to receive a Deadline Reminder Notification. 5 hours after that, if Person A still has not completed the workflow step I want the workflow item to go to Person B?

2.  when it goes to person B do we have option to keep work item for both person A and B or it will be only B?.

Also my workflow is having step - BLOCK Step which sends work item to multiple users at the same time for some scenario's and required approvals from all users.

Can someone please let me know how I can implement this.

Any help is much appreciated,

Mohan.