I have a 64GB Corsair Flash Voyager GT thumb drive (USB 3.0, compatible with USB 2.0). I need to format it in FAT32 as a single partition. The allocation unit size must be 4Kb. I know how to format to FAT32 but Leopard (OSX 10.5.8) does not have an option for choosing the allocation unit size. Is there a utility that will allow me to do this?