NTFS should be fine, though on older (non-DroidBOX) Android devices I had to use a utlility for non-FAT/FAT32 partitions.
If you can choose (and don't have files over 4Gb) then FAT32 partitions will be easiest.
Regarding the size, I've heard a limit of 2Tb being mentioned previously. If your drive is bigger than that, you could try first splitting it into two partitions on your PC.
If you have problems and your drive has a mini USB socket, see if you can find a mini USB to 2X USB plug cable somewhere in your home (some portable DVD writers also use it). If you can't find one, a mains-powered USB hub should help provide enough power to the drive.