Scholarly editions of the Amarna texts are published in transliteration in the Amarna Corpus, a component of Oracc: The Open Richly Annotated Cuneiform Corpus. Shlomo Izre'el's transliteration of the Amarna corpus is at The Amarna Tablets. All of this is also open access.
Readers interested more generally in Amarna may also wish to examine Barry Kemp's Virtual Amarna Project, openly published in October by the Archaeology Data Service, and some archival video footage of 1930s excavations at Amarna published online by the Egypt Exploration Society.
And see the Amarna Virtual MuseumAmarna in Pleiades