Many longarmers offer basting services for people who hand quilt. You have the advantage of putting all three layers together smoothly, setting your machine with the channel lock and long stitch length and basting the layers together. This is a service that many quilters would appreciate as it keeps them from having to crawl on the floor and pin or baste their quilts. I think you can do a 4" grid which should work for most quilters.
You could check other longarmers' websites for pricing for this service.
Debbie