This is only based on trial & error there are several options but the one that seems to be most effective for me is shipstation. I can have as many store fronts as i want. Example: at one point i had two active ss websites with different stores, ebay and custom in person orders via square. I can manage all orders at once. All order go into the same dashboard. I there process them into one big batch do EOD and have everything picked up together has saved me soooo much time and it works the best for me currently.