Bokken swords: wooden vs. cold steel?

Me and my friend are having this Zombie-apocalypse survival kit making contest, so by the end of it we can have people vote on who they think would survive longest. I've chosen a wooden sword/bokken as my main weapon, because one: I am a HUGE anime fan and thus like Japanese swords a lot, two it seems light to hold and to be low maintenance, and three it seems like it would be a decent weapon. But reading the reviews on these swords on Amazon, it seems that these things are not unbreakable. I have around 20$ left in my budget. I can either buy two wooden bokkens (http://www.amazon.com/gp/product/B001GMQ28K/ref=ox_sc_act_title_2?ie=UTF8&m=A1IP5Q3GWK9OUR , http://www.amazon.com/gp/product/B000EVPJXI/ref=ox_sc_act_title_1?ie=UTF8&m=AWO5MMT7WRHRV) or one cold steel bokken( http://www.amazon.com/Cold-Steel-Bokken-Polypropylene-Handle/dp/B0009QRRUG/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1309703279&sr=1-1 ) . Honestly though, I don't think a wooden bokken would fall apart from brains/skull-smashing alone(zombie apocalypse, remember?). BUT a steel one is obviously more durable and can be used to break stuff, also doesn't rot like wood sometimes might. I'm leaning towards the wooden ones right now mainly because the wooden ones have cord-wrapped handles, which I like a lot(and the second one would go great with my shinigami cosplay), and I get two. What do you guys think? which one should I get?