I can send you a priority box with a bunch of Red Oak acorns, and a paper bag of mixed wildflowers (wild bergamont, aster, goldenrod, blazingstar, rosinweed, joe pyeweed, purple coneflower, prairie coneflower, black-eyed susan, and probably some others...that's what I just picked yesterday). If you want specific wildflowers, I can collect those separate. I can get some grasses as well, little bluestem for sure, and then the ones used in WI CRP and Pheasant Forever habitat mixes (probably big bluestem, indiangrass, and some others).
I don't clean the seeds much, just try to pick them fairly clean. A lot of seed will fit in a small priority box.
I generally just collect in a large paper grocery bag, dry them a bit and mixed them around really well, and then spread them on the new site before winter.
As far as apple seeds, I'd need enough to make sure I had some germinate and then have a good chance of have some of those make it. What rates were you seeing with the ones you started?