I was browsing Orchid Press and saw this under their new titles, I thought some people here might be interested in it.
The Armies of Angkor
Military Structure and Weaponry of the Khmers
by Michel Jacq-Hergoualc'h, translated from the French by Michael Smithies
First English edition, 2007. 200 pp., 4 plans and 154 line drawings, bibliography, index, 24.5 x 17.5 cm., hardcover
http://www.orchidbooks.com/ba_cambo.html#armang