Personally for the number of shots you would get from a roll of film (4?) you could use regular film holders and just make a mask for your ground glass for composition which is what I do. But then i am extremely cheap and really don't do alot of panoramic shots.
I guess you could, I've got guidelines drawn on my GG for different formats, as well as using cut-out masks... butI'll tell you, I'd rather get six (6 shots when shooting 6x12) shots to a roll than one to a sheet when it ends up in the same format. Just me though, I like 6x12, it's kind of a 'fat panoramic', but if you didn't shoot wide very much, then I guess a whole sheet would do. The up-side of that is, if your wide composition doesn't work well, you've still got the rest of the full 4x5 neg to fall back on.
My goal in life, is to be as good a person as my dog already thinks I am.