Hi Ismail,
It's pretty hard to get decent Ipe in South Africa. Although that board should do. Listen to what Roy says and you'll be fine. Haven't seen a finer bow builder of this type of bow anywhere. Once you've got a few under the belt, and you've collected a bit of data on the type of wood you are using you can start messing with width ect.
Wish we got o's age in SA.
PM me if you need any help, good luck.
Pete