Personally, I think that configuration above is great.
SSDs are really fast, which means everything runs faster because the OS can access the files it needs to run far quicker. They are also more shock resistant and can withstand more ware than a HDD before failing.
HDDs are alot cheaper (GB/$) than SSDs, and that about all they have going for them. They are rather slow, large, and require some sort of drop protection.
SSHDs are a combo of both. They have about 8GB of SSD built in, which gives enough room for the OS, but not programs. They are also cheaper than SSDs, while only slightly more expensive than HDDs.
As for a fusion drive, I don't know about these but if I where to guess, I would say its like a SSHD with two separate drives merged into one digital drive. Possibly @danj could explain better.
RAID doesn't really apply here, as it is for cloning a drive or splitting the bits into parts for transferring onto each drive faster. RAID will only slow the SSD down.
If I where you, I would just have two drives. My SSD with my OS and programs, and my HDD for videos, pictures, music, etc, etc. Hope this helps!