glazing spline/bead

These glazing strips are fairly rigid plastic with a roughly 3/4 inch side that runs beside the IGU and into a slot in the sash. The IGU is 7/16ths. There is a rigde on the inside and on the outside of the 3/4 inch side. The other side is approximately 1/2 inch and flat with no ridges. The 1/2 inch side sits flat on top of the glass and appears as the bead around the window. I may need between 250 and 300 linear feet.