I would ask myself how many of these quilts will I make and quilt is a specific time period...say 1 year? Depending on that answer I would base my decision on that. I would also look at different LA services. Many will do custom work at usually .03 cents per square inch, yes that's a lot of money but if you are only doing 1 or 2 quilts a year that large and aren't planning on doing quilting for others to off set the cost it may be worth it to pay to have it done.
Do you have room for a quilting machine and is that really something you want to learn to do? It does take a bit of practice and commitment.
The person you spoke with about the quilting apparently only does edge to edge pantographs but there are a lot of people who do beautiful custom work. I know Chrisma on this blog had posted photos of some gorgeous work she has done for clients and I'm sure there are several more.
Good luck and let us know what decision you make.