It was brought to my attention that Brandywine Photonics sells a special sensor said to be optimized for multispectral imaging, the FBX-2. The sensor has a number of interesting features. While the main version has 2056 x 256 resolution with 15um pixel pitch, it's said to be available in HDTV, 25MP, 1 GigaPixel(!), and butt-able array formats. The broad spectrum QE looks very good, especially 30% at 1000nm:
The read noise is said to be <10e-, and the "well depth" is 300K (not sure what are the units of this one).
Thanks to OSP for the link!