I just purchased a Brother PQ1500 with a 9" throat to use for FMQ. The Brother only sews straight stitches and sews at 1500 stitches per minute. I chose it because it had the features I needed for the setup I'm putting together.
Other machines with larger throats are:
Babylock Quilters Choice Pro
Pfaff Grand Hobby Quilter
Janome 1600P
Jaome MC6500/6600
Elna 7100/7200/7300
Viking/Husky Sapphire
Janome Horizon
Bernina 830
Juki 2000QI
Some are only straight stitching machines like mine.