Does anyone have experience or information about configuring a SeaRey for IFR flight rules. Either upgrading a Classic Steam
panel, or building with glass from the beginning. What works? What doesn't?

It has been done, Mike--although not by many, as the SeaRey was designed primarily for flying fun on and around liquid water, rather than inside clouds. If you have a SeaRey, why not join STS, the Searey Technical Site, where you can find like-minded SeaRey owners and builders and the best technical info available anywhere. Click on "Help" in the upper right of this page. Enter your contact info and your kit or serial number, and an STS administrator will email you pretty soon.