Lion : Assigning a fullscreen app to a space
In Lion, the only options you have to manage the order of spaces are...


System Preferences &#x2192; Mission Control &#x2192; Automatically rearrange spaces based on most recent use
Manually drag spaces in Mission Control


The shortcuts to switch between spaces and desktops are set in...


System Preferences &#x2192; Keyboard &#x2192; Mission Control


But, you can only set direct shortcuts to Desktops - not any space.