Landing page and Category layouts need to be different

Been having a discussion in another thread about being able to override the default layout for ‘Category’ views.

For example, the default layout on my site is ‘Content / Sidebar’. However, I would like the ‘Category’ view to be full width, suppressing the sidebar.

Thus the following page (Content / Sidebar):
http://www.stmaryschessington.org/new/

Needs to be a different layout to (Full Width):
http://www.stmaryschessington.org/new/category/thoughts/

Is this possible?

Thanks,
Aaron