You're on the right track with the dual fuel options, which give you flexibility. For your needs, 3500 running watts should do the job, covering the sump pump, lights, fridge, and iPhones. In terms of brands, Champion and Westinghouse have some good models in that price range. I've got a Champion myself, and it's been solid. Check reviews to see what users are saying, too. Oh, and in case you're still hunting for more info, you might want to check out stuff about tidal energy. It's a cool way to explore alternative power sources.