There are roll film backs available for the 2x3 Graphics which are usable without modification if you have a "Graflock" back. This consists of two chrome pieces top and bottom on the back that unhook and allow the removal of the ground glass and focussing hood. There are two sliding brackets that will then attach an alternate back to the camera. If you do not have a Graflock back it is still possible to use other backs; but it would require some modifications, which, although not difficult, would make it unfeasible (in my opinion) to switch back and forth from cut film back to roll film back.
Assuming that you have a Graflock back, there are available what are called "Grafmatic" backs which attach to the camera and hold 6 sheets of cut film in individual septums.
A roll film back would need to be one designed for the small Graphic.
As for the lens board, unless you have one of the earlier models of this camera, it will require a metal lens board with a lip that fits into a goove in the lens standard.
You might want to check out graflex.org, it is an excellent source of information regarding these sorts of cameras.