Your original question: Is there any theme available that allows alphabetical ordering of posts? was answered correctly with a "no".
The open source community is full of creative designers who design themes with unique features and the themes at wordpress.com are not "cookie cutter" themes. I am well aware of the features of Vigilance as I used it for a long time. Vigilance lacks dropdown menus. If you are looking for a theme that has dropdowns to child pages from parent pages I can supply a list.
Currently, the Bueno, Enterprise (2 dropdown levels - 1st level Pages & 2nd level 10 Categories) ), iNove, Inuit Types, Monochrome, Neutra, Notepad, Sandbox 1.6.1, Structure, Twenty Ten, Titan and Vostok themes are the only themes that have dropdowns to child pages from parent pages in the top horizontal menu.
Happy blogging. :)