the uefi should boot from the first drive that has a valid boot partition. . if you have multiple boot partitions then you would have to select the drive to boot to from the boot menu. if that is what you want then I don't believe it matters if the partition is at the beginning or end of the drive. I would try and shrink you partition by about 500mb partition and format the empty space as fat32 then use the steps I mentioned to setup your windows boot.
no killzone and killzone 2? loved those games