Hi Heba... I use prewound bobbins, I have bought them from APQS. I have found them much easier then wounding my own bobbins.
The prewound are on plastic spools.
As far as the Hartley Fence, I have one and have tried to use it once. I am ordering a book from Myrna, (she is also on line and has a great website.)
I asked her about zippers also, check out her website and see what she has.
Barb Wetzel
Ivy Corner Quilting
Altoona, Iowa