Nice link. That's going on the workshop (shed) wall...
I would say that a longbow, especally a self bow is not the easiest thing to start with. This article assumes you have the perfect bit of wood. No grain, no knots. I've never found a bit like that. Castello box and lemonwood come closest. You could almost get away with it with hickory but it would be very heavy in the hand.
If in doubt go flat, broad and long...you can get away with a lot more. Or start with a laminated stave.
David.