large storage

I am trying to have my box store on a 64gb usb and eventually have 1.5 tb. I am not able to format to FAT32 but only exFat and NTFS. I have been trying to look and find a way for the piratebox storage to use exfat or ntfs but I have had no luck so I figured someone on the forums would have come across this problem and or solution as well. Thanks!

I am running a rasp pi 2.

-nei