I made my own extended run for two Honda 2000s using a plastic 6.5 gallon boat tank, a couple of boat fittings, and two fuel lines. You just need a tee at the boat tank, with two of your favorite boat fittings on it.If you are like me and don't have a boat, I bought what they had in stock to complete the system.
I wasn't sure if the system would suck air in when I was only using one generator, but it doesn't. The most I was out was one length of fuel hose, and a couple brass fittings if it didn't work. As far as I know Honda is still the only one that uses a fuel pump. I am not positive on that.
BTW, regarding Hondas costing too much, I just turned 1000 hours last week on my newest Honda. And that is just since I put the hour meters on them. They both have WAY more hours than that on them. I couldn't even venture a guess as to actual hours, but they are still flawless in operation.