Custom template for each page

there are a few way you can do that:

  • Template Hierarchy – each page with is own theme file using page-{ID/slug}.php
  • Custom Page Templates – Individual Pages can be set to use a specific custom Page Template from the edit screen.

but if you are just looking to change whats on the sidebar then there are a few plugins that can help you with that:

  • Widget Logic – lets you control on which pages widgets appear.
  • Dynamic Widgets – lets you dynamicly place the widgets on WordPress pages.

and there are even plugins that let you display the whole sidebar on a page to page basis: