Virtuemart - Multi Vendor

We have done (and will continue to do) the bulk of the work setting up our virtuemart site. We want to turn our virtuemart shop (newly established) into a multi-vendor hub. However, having difficulties navigating the best way to implement this. I hope and expect that 1 or 2 hours of advice, assistance to get over the hurdle would be sufficient and we can continue the practical implementation from there. So specifically the advice and assistance we need is: 1) Setting up 10 - 15 vendors 2) Selecting the precise payment pathways that virtuemart offers. (ie: who gets the money, how, who pays any charges, ensuring invoices system setup correctly and who pays who when transaction complete? optional third area is implementing selective extensions to assist with multi vendors administering their own shops on the front end. This is optional because, at least initially, the central shop is willing to receive updates, new products by email and update the virtuemart accordingly on behalf of the vendor. In a perfect world we (and they) would want them to control it themselves. However, this may not be practical within the resources we currently have.