you are right having the pieces all run the same way. Your quilter will need to put the seam going horizontally so that it doesn't get saggy on the ends as she rolls it, risking puckers and tucks. you already know how much extra they want--make sure you have that much extra of batting if you are providing it too. On the selvages, if you don't cut them off where you piece (leave them on the sides that aren't the seamed part)you can snip every so often to allow for that uneven shrinkage--but I think it's easier to cut it off. Also--think about how you want it quilted--you will be happier with the result if the quilter knows what you are wanting and it will effect price too. You don't have to have it all worked out--that is part of the reason you are going to the LAQ--but know whether you want heavy quilting or just enough; geometic or all curves; Edge to Edge or perhaps an all-over with a separate border treatment, etc. also think about thread color--do you want it all one color or several different ones to match the fabrics. Lots to think about but also good questions for you and the LAQ to discuss.