It just sounds like you need to list your needs to find the right solution @mesmergoat? Details like the number of vendors, products, checkout options and other metrics you anticipate would be helpful. I would for instance offer a different solution if for five (5) vendors than I would for fifty (50). Having a clear set of requirements will give you the ability to have the best outcome. I hope that helps?
...turns out that my two cents is worth less or more depending on the current exchange rate.
roy darling *my posts seem a lot shorter in my head