I used oak boards for my decking 20yrs ago. Replaced it last year mostly due to the portion of the deck on the north side of the house. I used green boards & butted them with no gap. Worked fine except for the north side, there they never dried enough to leave a gap & rotted.
My advise would be to use 5/4 or thicker boards & make sure they will be gapped btw boards.
Brettski is right on pre drilling holes. That is a must. IME oak doesn't cup as bad as treated pine, at least it wasn't a problem with my deck which was apx 800 sq ft. Also as they weather the roughness softens & isn't much of an issue even barefooted.
