What CUIX file(s) do you have loaded? What Workspace is current? What you describe does not sound like the AutoCAD Architecture standard installation (ACA.cuix; Architecture Workspace), which does not have a Visualization ribbon tab (at least not in the ACA 2010 release). Then again, neither does the ACAD.cuix file. Perhaps you want the Render tab? Try right clicking on the ribbon some place not directly on a tab, panel or tool. You should get a context menu that includes a flyout called Show Tabs. Hover your mouse over Show Tabs, and look at the choices on the flyout. Any that are unchecked are not currently displayed in the Workspace. Select one that is unchecked to make it available.
When I go to customize the workspace its actually showing the tabs I require in the visualization workspace but it isnt displaying them on the ribbon, see attached screen shot, any ideas?
The attached screen shots are confusing. It seems like you have a plain autocad workspace current.
Do not confuse ribbon customization with workspaces.
It does appear that you do have a visualization workspace.
Go to the bottom right of your screen and click on the Cog icon to switch workspaces.