If you haven't seen it, you might be interested in Japanese Death Poems, Written by Zen Monks and Haiku Poets on the Verge of Death
, by Yoel Hoffmann: http://www.amazon.co.jp/Japanese-Death-Poems-Written-Monks/dp/0804831793
It discusses the farewell poem in Japan in general, and contains quite a few of them. It shows the romaji for some, though the majority are in translation only.
A lot of interesting material in that book. While many Zen monks and laypersons did leave behind death poems, Hoffmann reminds that there were others who refused to do so, or who openly disagreed with the custom. It's more accurate I think to view the death poem primarily as a cultural custom that some Zen practitioners followed, rather than something connected specifically to Zen practice or to the Zen understanding of what an ideal practitioner's death looks like.
In that vein, Hoffman's book also contains a few instances of poems which mock death poems. My favorite...
The dying monk
looks as if
he knew it all.
In any case, I suspect you'd enjoy it.