If I'm going to go to the trouble of running a USB pointing device, I'd use a nice big trackball there.
On the PS2 port, I'd keep a standard bottom-end MS or Logitech mouse for use when I need safe mode. The USB driver doesn't come up in safe mode on all systems.
There may be a 'USB legacy device' or 'USB Dos Compatibility' option in BIOS that you need to switch on to see the USB pointer and keyboard.