FAT16 is limited to 2 gig's and that is the MAXIMUM size partition you will be able to create during Windows NT 4.0 installation. Once the system is running, you can create a very large NTFS partition, the last time I THOUGHT about it, it was about 4 TeraBytes..
On the other hand, FAT32 allows for a considerably larger partition size than FAT16, so while installing Windows 2000, you can create a fairly large partition and then convert it to NTFS without any problems..
Regards