I use the guide that's attached to the bed with a screw and the 1/4" foot with the little guide. I've found they both work but I like the foot with the guide.
The 1/4" foot with the guide is wider, kind of like a zig-zag foot and seams to work better.
I got the 1/4" foot at Sew-Classic. The bed mount guide came in various and sundry accessory kits we've accumulated over the years.
Joe