Marc-
not to sound like a smartass, but maybe you should look at building your own. Then you can get exactly what you need in the camera. Just get a set of replacement bellows (bag and normal) from something like a Shen Hao, and build the rest around them.
Another thought, have you looked at the Bulldog kit? It is a dedicated wide-angle 4x5 camera, with limited movements. They're fairly inexpensive, look quite well-made, and are pretty straightforward to assemble. I'm not sure if they have all the movements you're looking for, but they're a lot cheaper than an Ebony.