craftgrrl | (no subject)

I have a Singer model 1120. This guy:

http://www.sewingdirect.co.nz/singer/1120ix.jpg

I want to be able to use my machine to do quilting on the many unquilted quilts I have sewn recently. I googled "Singer model 1120 quilting foot" and came up with a crap ton of different kinds of feet and things.

So... what exactly is it that I'm looking for?

So I'm looking for a free motion or darning foot, but my google-fu is failing me. Halp?

Is one of these what I want? Are they the same thing?

http://www.sewingshop.com/index.asp?PageAction=VIEWPROD&ProdID=63

http://www.singersewingsandiego.com/siemdafo0.html

The all metal one seems more sturdy, but costs less. Why?