Ted,
Hold off on the oak, find a good piece of hickory. Hickory boards work very well and hickory will take violating the rings much better than other woods. A 68" 1x2 hickory board will make a great D bow.
Here is a link to Jawg's site. Hell of a bowyer. He visits here once in awhile.
Read about board bows.
http://georgeandjoni.home.comcast.net/~georgeandjoni/
