i'd be interested in this too.
i have the 2 captain's chair arrangement and find that the space between the two chairs' arm rests is a bit tight (have to go thru side ways and usually catch my jacket on a arm rest) also constant rubbing on the arm rest due to tight space in passing has cause the arm rest to look terribly worn.
A side bench arrangement would allow for an additional body to sit up front and eliminate the tight space between the 2 chairs.