honda gx or robin-subaru based. Nothing else is worth it, unless you have the potential to run with really low-grade, sub-par fuels for long periods of time - in which case a flathead B&S is the best choice!
I have a 1700W Robin Subaru inverter generator, which puts out AC and DC... I love it, and it is super-quiet. I dont have sump pumps, but this is a good unit to run the refrigerator, freezer, and a few lights.
My inlaws deal with a LOT of outages, as well as hurricane risk. Ga$oline generators were just too inefficient. They have kubota (IIRC) diesel gensets, and they love them!