I have done a 101x101 on my Brothers 1500- the larger the quilt the harder it is but also the cheaper it is. (FREE) I use spray basting-( 505 now avaliable at Joanns) which make the quilt much lighter and easier to move around that using pins.
Also using a batting that requires farther apart stitch such a W&N is a good idea.
Also the Bernina store in Twinsburg rents out its long are for use at a hourly rate. You need to take a class on how to use the machine but then you can do your own FMQ on it. Cost?????? not sure but may be worth checking into.