Returning this to the subject of the thread, it occurs to me that my cousin in NS has two massive oak trees, which fill her lawn ankle-deep with acorns each autumn (she fills her municipal green bin with them several times over, while exercising the nether reaches of her vocabulary). I'm pretty sure I can bespeak as many as I want to experiment with.
No idea of their tannin levels, but when you're just playing it doesn't matter if they need longer processing.