I can get 8 foot, inch thick, by 6ish wide ipe boards at my local mill. I can sort thru the pile and pick grain orientation, but usually the grain is so fine that it is quite hard to see it. I usually pick what looks best for BBIs, and although I have had my share of problems, it has never been due to the grain on ipe.
Not quite an ipe stave, though. If you want boards, let me know. I am sure we can work a trade out, no problem.
Russ