I don't know if Fedora's going to be good for that setup.
Depending on how much memory it has I'd skip the swap partition.
Then I'd probably put / on the Internal and /home on the SD card. But you should probably format the SD card as ext3 because FAT32 for /home partitions is probably not the greatest because FAT is not POSIX compatible (you'll have issues with permissions and ownership - apps might not work right).
Or, if you want to leave FAT32 on the SD card (might be nice if you want to pull the SD card and put it in another machine). Then mount the SD card to something like /data and store personal stuff there.
Also consider LVM.
As for squeezing Fedora onto 4GB, I just don't know. Let's just say it'll have to be a light install. Consider the XFCE spin. http://spins.fedoraproject.org/
I'd personally consider something lighter like Puppy or DSL.