Spinning Arm Sump?

[kpris]

I've been planning on setting up my first marine tank soon. A 4ft FOWLR tank and managed to buy a tank that came with a sump (2ft) and spinning arm etc...
The sump is kind of like so:

| |
| | |
| | |
|_________ |_____|

top view:
________________
| | |
| | |
|__________| |
|_______________|

So my question is, how am i supposed to set up a sump with what I've got? What's the difference between a spinning arm sump and a matrix/overflow one (i mean other than the obvious set up differences, which is better than the other? why?)? How is a spinning arm going to help anything?

Suggestions on how i should set this up? What should i put in it? Ahhhh XP

Also in case you're wondering the space on the right is just big enough to fit the protein skimmer.

 

[kpris]

Oops accidentally posted the same thing twice XP

Also my diagrams aren't coming out right. Doesn't like the spaces.
Basically it's like there's a smaller tank (in height as well) inside the larger and pushed into one corner.

 

[SkiFletch]

Well, I'm confused . Maybe try and use paint or something and upload a picture?

 

[kpris]

here we go:

diagram~