Great job on all your quilts. If you send your LW out to be professionally quilted, hopefully you will find one that can have it ready for you by Christmas. Most I know are already taking Christmas quilts and many cut off in October.
An all over is the most economical way to go. Pricing varies by area and also by density of design but for the most part it averages .015 to .025 per S/I Some places a little higher, others lower. So if your quilt finished as the pattern states at 84 x 84 an E2E design can run anywhere from $106 to $177. You would have to supply the backing and batting or purchase it from the longarmer.
Custom quilting would probably start at around $250 to as high as a $1000 depending who does the quilting and how detailed and dense it is.
I have seen this quilt done both with E2E and custom and quite honestly the piecing makes such a dramatic statement the quilting didn't make a bit of difference one way or the other. It looked great both ways.