Kurt, the two most recent companies I had do stone countertops for me both had a pretty sophisticated electronic measuring set up that I'm confident could let them do an acceptable job of what Deb wants. It takes them a while to get it set up, but once set up they mostly stand back and let it measure the entire top and while it's computing exactly what is necessary it is even transmitting that information back to the CNC machine that is going to do the cutting of all the pieces. The operators tell me that at least in theory they could order the slabs cut without ever having to return to the shop. Both said they were not yet confident enough with the equipment to actually try that.
The most recent one I did was a three-wall kitchen with a sink cutout and slide-in stove space. The two miters for the turns were as perfect as I've seen done and the rest of the fit was equally impressive. I'm figgerin' that layout system likely cost about as much as the CNC machine.
I still don't think installing the splash first and scribing to it is a good idea, but I do think it can be successfully done. Again, I expect even my guys would be inclined to charge a bit more, but that may be an incorrect assumption on my part.
I don't think it would take more than one trip to measure, but I gotta think it would take two trips on accounta I believe they would want to install the splash first and then do the measurement for the tops because the splash pieces would not be the same shape as would be the walls without the splash. And now that I think about it, I'm not entirely just how accurately they scribed the walls on accounta it didn't really matter much on my jobs. It sure knew where everything else was, though.
My opinion; worth price charged.