Last year I researched the same question for myself. I chose the Janome Horizon 7700. It has 11 inches for the throat space. I was able to quilt a king size quilt with very little difficulty and I'm a beginner quilter. I chose the Horizon over a long arm because of the cost and the size of the longarm.
It took me about 3 months of researching to make my decision.
Good luck
Vicky