Hi,
Is there any agency with a end user agreement that would allow this type of usage?

Like placing a photo of a person as a "placeholder" on a POD / Zazzle invitation, where the buyer swap for their own photo?
Like in this example:

https://www.zazzle.com/s/photo+graduation+invitations

I see a lot of shops on zazzle using photos that look like they are from microstock or public domain. But the way the licenses are so tight these days, I don't know.

Or is there any photog selling packages for this type of usage?

I'm really not sure what you're asking.

If you want to use photos on Zazzle products, buy the extended license.  Most sites offer this.

If you are trying to set up your own version of Zazzle, and need pictures to use to show how your products look, an ordinary license will do, so long as you don't actually sell the products with those pictures on them.

But, you really should get the extended license.  My experience with customers is that they will want to buy what they see. 

If you really want to keep it simple, take some snapshots of your favorite pet, and use those.

I'm really not sure what you're asking.

If you want to use photos on Zazzle products, buy the extended license.  Most sites offer this.

If you are trying to set up your own version of Zazzle, and need pictures to use to show how your products look, an ordinary license will do, so long as you don't actually sell the products with those pictures on them.

But, you really should get the extended license.  My experience with customers is that they will want to buy what they see. 

If you really want to keep it simple, take some snapshots of your favorite pet, and use those.

Yes I would have thought the easiest and cheapest thing to do is upload your own pics