A cube van will give you more room in the back, but it'll drain your wallet when it's about fuel. Also you might be pulled over pretty often since some cube van drivers are hauling heavier freight that they were supposed to...
I've been in this business for over two decades now and yes, I can say it can support a family. It takes some sacrifices (being away from your family for long periods of time), but again, it can support a family.
Believe it or not, I drove my Savana for 10 years (almost 800,000 miles) and I changed only one headlight (plus 2 brake lights and about 4-5 tag lights).
I believe that was the idea for raising the rates, to "kill" the small carriers by pushing the O/O's to those larger carriers that offer their own insurance for way lower rates.