Get the PFS3_53 archive from Aminet and install it. It contains the complete distribution with tools, documentation and everything. Just use PFS3aio when it talks about PFS3 or PFS3ds. You can as well use PFS3ds, aio brings no benefit for you.
Once you have a file system which supports accessing outside the first 4GB of a harddrive, you can make partitions as big or as small as you like. The issue is the position of the partition on the harddrive, not its size.