I've been looking in duel generators also, but my knowledge is front Internet searchE's only, sorry no direct info.
First, connection kits are just 3 wires connecting the gens. Just make sure the have the ends that fit your gen. (Some makes specify that they have a RV connector)
Second I've read that you can mix brands! I would be skeptical on this point, but they also point out that you can mix gen. sizes!
Last is Honda has the name and reputation, but also the $$$. I bought a Home Depot Ryobi gen. That is a direct competitor of Honda, but with all the bells and whistles. Mine was a recon. but looked new inside and out. Paid $299 and list is $599.
Last is bells and whistles, blue tooth! I thought it was a joke at first, but when I tested the gen. for the first time, it was great. It was less than 20° outside the RV. I started the gen. in the cold hooked it up to the RV, went inside of the RV turned on a bunch of things including me 120v space heater. It got warmer inside. I was able to monitor gen time left, fuel, and load from my tablet. Then shut it down. Note the LCD screen on the gen is next to the outlets, so to see it I would have had to get down in the snow to see it, bluetooth good.
I have no connection to Home Depot except for a CC.