Here's online access to a digital Nestle-Aland prototype at the University of Munster, shared by the Institute for NT Textual Research. Here's a link that can help guide you around the site: http://nttranscripts.uni-muenster.de/guide.html Three different Greek lexicons are linked to the text as well. It also shows which manuscripts have or do not have certain readings as well as comments on transmission of those texts.
Here's another link to great audio lectures. They were delivered at a Conference held at Charlotte Chapel Church Edinburgh on the Reliability of Scripture. Peter Williams, Dirk Jongkind and Simon Gathercole guest lecturers.