I'm really tempted to mod another light gun, either a second Guncon 2 or maybe a sleek Gcon 45, and a part of me was thinking I could MAYBE try the #gun4ir... except the fucking thing is closed source, paywalled, and only has a Windows utility for calibration et al.

Meanwhile, the open source Samco project (and the magnificent Prow7's fork of it) handles the settings on the gun itself, and is slightly cheaper to make, so it's more universal and slightly less of a hassle.