You all have me thinking about octagonal sticks now, the only octagonal weapon i know of are nunchuck's - has anyone ever seen any suppliers for octagonal staffs? if i can find one i may cut it down for kali sticks.
As for sticks my favorites are my spotted gumtree sticks - but as reiki advised leave them until you have practised a while.
The only octagonal weapons I've come across are nunchaku, sais and tonfa.
I haven't seen any octagonal bo or sticks.
I think they'd be hard to work with but would hit with more impact than the round ones if my experiences with nunchaku are anything to go by.
Sensible lad, stick to the rattan until you are very experienced. Hardwood can do serious damage to bones - especially hands if used by beginners!