If you are hoping to buy only 1 genny how much weight are you prepared to lift? Most of us get by with a Honda 2000 for the trailer however that is not going very far powering the house without some very serious power management on you part.
Living where I do hurricanes are an annual threat. The last direct hit we had the power was off for OVER a MONTH. I did not have my own genny then. I do now & it is a 5kw gasser which powers the house, no AC, very easily. Yeah, it is noisy but it was cheap & I am set up to plug it in just on the house side of the meter, remembering of course to turn the meter off. You can't get much more basic than that.