Yep... that model does have only two Firewire 400 ports. So USB2 would be less expensive as they're similar in speed.
Update: So I went to my local Frys store and all they had was UBS enclosure so that is what I got stuck with. As of this very second Ian installing Leopard through target disc mode using my friends laptop and her optical drive (mine seem like it is shot) 28 mins left gotta run to church hopefully it is done when I get home!