I use this one, 1/4" Foot w/ Guide, High Shank #767820105 from Sewingpartsonline.
I had to try a few things before I was really happy with my piecing. I found that for me, setting the stitch length a tick under the 2 along with using a smaller needle (Organ HA X 1 130/705H 15 X 1 size 75/11PD) helped get the results I wanted. Those needles are expensive but I'm hopeful that they'll last longer. Hope you're enjoying your new machine.