one more update here. After hassling with JPI and aircraft spruce I ended up cancelling that order. I instead went with the Insight G4. They have a package for Skymasters that includes the whole engine monitoring system. They also have an STC for primary on cylinder head temp, exhaust gas temp, and TIT. They have also applied for a future STC for primary on oil temp, oil pressure, and MAP.
The G4 system is not shipping yet, so they are loaning me two G3 gauges until a single G4 comes in.
I also contacted Shadin and they can sell me a used gauge that will connect to the G4 fuel flow sensors and give me the STC for primary fuel flow on the shadin unit.
In the end it was a much better deal than JPI with more features.
http://www.insightavionics.com/g3.htm
Brian