I had written an answer explaining
fdisk partition codes. After a bit of research I decided it was completely wrong and deleted it. According to this page (which I imagine you have seen)
freebsd-ufs is indeed the correct file system type.
I guess you are running into problems because you have too many primary partitions. Only four primary partitions are allowed. Since you already have 2 other OSs installed, you probably already have the maximum four allowed. So, what you need to do is delete the empty 64GB partition and recreate it as a extended instead of primary partition. I would recommend you do this through
gparted on Linux but you can probably do it through the freeBSD installer as well.
Once you have converted the primary 63GB partition into a extended one, you can go ahead and create other logical partitions within it and install freeBSD on one of them.