Great camera, and there is a LOT of data to be gleaned from a good scan of a well exposed piece of 120 film. Both it and the Mamiya RZ line show some excellent bargains right now, an both can be adapted for using a digital back if/when you get there...
The GX is a bigger heavier camera, that allows for tilts and shifts with all of its lenses. (Stay away from the "S" versions if you want lens movements as it does NOT allow tilts or shifts.) Lenses also tend to run a little slower and widest is a 65. The RZ is smaller and a bit lighter (but still no feather weight). Only offers lens movements with the tilt-shift adapter or 75 shift lens, but also goes wider with a 50 and even a 37 fisheye. Both offer a ton of nifty accessories, finders, etc.
Scanner, a good Nikon or Minolta MF will serve you well as will a good Imacon flextite photo, but I'd suggest getting a new enough one it is a USB or firewire interface, not SCSI...
Best,