Deck ledger flashing options
Typically, an aluminum or galvanized &quot;z flashing&quot; as you called it, would be installed under the siding, over the top of the ledger and down the upper lip a little. Decking is installed on top of this flashing.
(Diagram not to scale)

Done this way there is no need for any of the other products you mentioned unless you have moisture or insect concerns from below the ledger.
I would not use vinyl or copper tape for this, any cracks will prevent it from working properly so it needs to be very durable.