Direct Drive Hub

I have many external devices connected to my laptop, and I am trying to figure out which way is the most efficient for my computer. I have 4 usb ports and 1 4 pin firewire, as well as a 4 port usb powered hub.

Here is my question, I have a external dvd burner with both usb and firewire capabilities and I am going to get a external hard drive. Would it perform better to have the hard drive and burner in series in firewire, or have one firewire and one usb, or both usb in a hub/computer direct?

I have 4 other usb items, so i need as many usb ports as possible (mouse, joystick, printer, mp3 player).
In response to the first answer.....

What about vise-versa? What if I connect my dvd burner via firewire and hard drive via usb? Since a usb hard drive is easier to find and my burner is already firewire?