C# - Creating A Dropdown With Data From Multiple Tables?

I want to create a dropdown of Vendors. I have a Vendors table in my DB, containing a VendorID and a CompanyID. The Company table contains a CompanyID and a Name.

I would like to have a dropdown with items that have the VendorID as the value and the Company Name as the text. But I don't know how to get the Name field from the related table to put in the dropdown, so I have the VendorID as the value and text. Here's what I have right now.

I'm passing in a model that contains this:

public IEnumerable<Vendor> Vendors { get; set; }

In my controller, I'm setting the value of Vendors like this:

MyDBEntities _entities = new MyDBEntities();
Vendors = _entities.Vendors;

Here is my dropdown list on the page:

<%= Html.DropDownListFor(m => m.VendorId, new SelectList(Model.Vendors, "VendorID", "VendorID"), "- Select a Vendor -")%>

I thought I could create a custom function - GetVendorsForDropdown - that would return only the data I needed, and changing my model to contain IEnumerable<Something>. But I don't know what the return type should be.