The Old Pine Box -- a sole proprietorship from Deadwood (no pun intended), New Mexico that makes coffins and wood furniture -- has a line of PETA coffins, which, apparently, are designed by "the folks at PETA": "these coffins allow you to voice your defense of all creatures even after your own voice is silenced. Every coffin purchased from this selection will result in a net contribution of $75.00 to PETA."
They cost $620 or $670, depending on the model. I intend to donate all my viable organs and then be cremated, but, if I needed a coffin, I would choose the one pictured left. Note that these coffins are not stock items and require a two week lead time, which I guess means: plan ahead? You can view the different PETA coffins here.