I checked on the members site and the floor plan shows one bed in each room upstairs and a sofa sleeper down stairs. Nothing mentions roll aways. The contac us number on the site is 877/743-5510. You might give a call and ask. As to mini vans I imagine they do but a check at a rental company web site could answer the question.
One of the configurations has a queen or king in the master bedroom, two beds in the second bedroom and a pull out coach in the living room. This same configuration has a den (downstairs) with a bathroom. Would you still need a roll-away?
We have rented minivans in the past, haven't needed one the last few years but I'm assuming they still rent them.
We've stayed at Paniolo Greens several times and have been pleased.
And you might find two regular-sized cars cheaper than a minivan. Or a full-size you keep for the week, and another car (or a taxi?) to transport your luggage from the airport. Paniolo is kinda far from the airport, but if you're going back to town the next day it might work.
We were on the Big Island this past January and rented a minivan for the 4 of us. Very comfortable. We also liked the fact that the windows in the back seats are much bigger than in car or in SUVs. This was a big bonus since 3 of us have cameras ready at any time to take a picture. Of course, I have to stop to do so, but the other two can take pictures while driving.