One had better HOPE they are the annual type (though it is a little late for those to be in flower now). The perennial everlasting pea is HYPER invasive and hard to get rid of (I saw banks of it along the sides of the highway on Friday, just smothering everything.)
Is this the flower farm that you're referencing? They certainly do have a lot of sweet peas, and their Willly Wonka Mix looks amazing!@Branching Out , you have done your research.
I used to order from Thompson and Morgan, then their N America presence sorta collapsed. They had such a huge selection of sweet peas.
The Farmhouse Flower Seeds (Washington State) is right in our neck of the woods. And, they sure seem to specialize in sweet peas. Johnny's has some.
Steve