OK just to wrap this up, I went down to Northern Tools about 45 miles away, and bought 1-Honda EU2200 and one EU2200 companion plus the Berg single gen sysstem, them didn't have the dual generator system but I figured I could work around that. And I thought I was buying a parallel cable kit but when I got home found that someone had swapped it for a 12V DV cable kit...heh.
Northern Tools had the cheapest prices I could find plus there was a moderately close store.
Anyway I ordered a cap at Amazon for $22 along with some 1/4" rubber fuel line for $7. Those got here today, you need to be careful ordering from Amazon they have the default delivery date set to weeks away. I bought some brass fittings at the local Hardware for $18. That got the double gen system set up, I just replaced the 90 deg fitting in the Berg system with a brass tee and worked from there. Once I got it put together I discovered that I need a quick connect in the new fuel hose otherwise it's going to be a PITA to get the cap off the generator. So I ordered one of those in nylon but the delivery time is two weeks. Brass ones were $45-70 the plastic one $10 and since it's for fuel hose it should be OK.
Still don't have the parallel cable but decided I could work w/o it for a couple of days. Started the two gens and shut down the Champion 3500/4000. And what a difference in sound levels. You can hardly hear the Honda's from 30 feet away. The Champion may be quieter than a Construction gen but don't come close to the Honda. I've made the claim that the Champion was almost as quiet myself during these threads and I was just wrong.