I asked my dealer this question when I bought my first Montana. The answer, at that time, was No. Montanas come with either the jackknife or sofa bed. In my case, the Jacknife.
I intend to find a "standard" sofa someday. I want a nice comfortable sofa that does not open into a bed. One that you can kick back on and relax and read a book or watch TV. Not one that feels like a padded bus bench.
Everytime I have had someone stay with me, they are asking for the Eddie Bower blow up mattress after one night on the Jacknife. I tried to tell them.