Vendor payments to one vendor: some subject to 1099 reporting, some not.

You do not need more than one vendor.  Just go to Vendors > Print 1099's/1096's and then map the accounts that need to 1099 reported on.  For example, if you buy from a vendor who is a subcontractor and he does subcontract work which is subject to 1099 reporting and you also buy materials from him which is not subject to 1099 reporting, you would map the subcontract work to the COA that you use for that expense and exclude the account used for the material purchases.  When you go to print the 1099, only the amounts in the Subcontract account will appear on the 1099.

I hope this answers your question.  There is a lot of help available for this in QB's.

Thank you, that helps a lot.  I did use the Help feature in QB but it was unclear to me that when you check the 1099 box in the vendor record n only payments to accounts that are mapped to 1099-MISC (from the Preferences) accumulated for the 1099.  In other words, If I make a payment to a 1099 vendor but select an account that is not mapped to the 1099-MISC, this payment will be ignored for 1099 reporting, correct?  Thank you again.

There are instances where the materials are included in the 1099. The 1099 instructions for box 7 (non employee compensation) say you need to include payment for parts or materials used to perform the services if supplying the parts or materials  was incidental to providing the service.