Things to consider on a used generator are has it been exercised and was it drained between uses.
I haven't read many complaints on the Powerhouse unit aside from finding the parallel kit. Champion does have a good rep in customer service and getting parts. You may also find it cheaper as I've seen it as low as $800.
2011 GulfStream Amerilite 25BH
2003 Ford Expedition with 435w tilting portable/ TS-MPPT-45
750w solar , TS-MPPT-60 on the trailer
675 Ah bank, Trip-lite 1250fc inverter
Sportsman 2200w inverter generator