GP Sorensen part # CSS40 $38.88 normally stocked (Advance Auto Parts)
It requires cutting the plastic back around the plug, and soldering the pigtail from your old sensor (or a spare HEP... same connector ) to the terminals. It also requires filing a flat into the plastic body of the new sensor in the same location as the flat on the stock sensor. Other than that, it's a drop-in replacement. The body is the same length, and the bolt hole is in the right spot.
I just got my Spirit running off of one today, so no long term results yet, but it's working great so far.
Maybe someone else can benefit from my experimenting. Sure beats paying $150-$200 for one.