Good question
@Zeego! I also vote for Rad (at this price point) or the trailer option. Trailers can be great, but they take up extra space when not being used and you may need to purchase an adapter or be careful which ebike you choose to make sure you can attach the trailer (especially if it has a hub motor vs. mid-drive). Unfortunately, I've responded to a few comments about EUNORAU customer support being limited, and I believe that their hardware is a bit cheaper than some of the others.... Rad tends to upgrade the little parts like having a wider cassette range, which is great for a cargo bike because it makes starting easier. They may also have a higher resale value due to the name brand recognition.
Magnum also has a good cargo bike for the money as well as
Blix, and I've covered them both back at the main site
good luck! Also, consider using a regular bicycle with a powered trailer like the
Ridekick... it's louder and kind of limited on space, but kind of neat.