If you want to make your own, look for coarse ground whole wheat flour. Bob's Red Mill should have something.
I used to use Nabisco graham cracker crumbs (in 5 lb bags of fine crumbs for foodservice) but they were out of stock for months earlier this year. In looking for alternatives, I found so many graham crackers with cinnamon added, yuck! So I feel your frustration a bit. Graham crackers, victim of the pandemic?
If stuck with mediocre GCs, you could try lightly toasting the crumbs to counteract staleness, or brown your butter and add a drop of vanilla to boost flavor in your crust.
