I think 6x17 is a fairly popular format, so there are several options between a Linhof and some obscure Chinese product. For example the Fuji GX617, to name just one. It is discontinued though.
Shift would be a useful feature. Groundglass is normally not useful, because there is no film magazine to replace with a groundglass.
There is a camera, however, where the film magazine can be replaced with a ground glass, and the image size can be changed from 6x6 to 6x17 without changing film or magazine. It is not cheap though. http://www.gilde-kamera.de