Sourcing multiple vendors from the SalesOrder

Does anyone know if it's possible to source the alternate vendors of an item so that the possible vendors and codes could show on a sales order?

I tried for a few hours but can't find the vendors list that would include the alternate vendors and codes for the items, all I can find is a list of the vendors not assocatied with any particular item.

Our current process involves inventory on demand so that we normally stock an item but if we don't, we get it from one of many vendors in the area and we have to open a new window to look at the item basic tab to see who the vendors are and what their part numbers are.   We are hoping that if we can view this data from the salesorder it will dramatically improve our approval and sourcing times.