Patsy, here are a couple of sites to get information on both machines and frames. Bailey has their own machines which can be ordered in 12 and 15 inch arm.
http://www.baileyssewingcenter.com/homequilter.html
Then there is this company with excellent buys, but most machines are 9 inch machines.
http://www.sewvacdirect.com/grace_combos.html
There is also
http://www.allbrands.com/products/abc0308.html
You will see there are different frames. Most will extend to about 104 inches. The one I bought has an extension for a King size, but the queen is 104 and is big enough for what I am doing now.
I am just learning, but I did a lot of research. Taking your time to compare and decide will pay off later.
June