I've got some pics of details on glass installation in my build thread. Lami is the way to go! 1/2" total (1/4 + 1/4) should be enough for your wall system. Use neoprene to set the glass. John Sayers' Recording Studio Design Forum • View topic - AudioGrotto Build Diary
There also should be hard neoprene setting blocks under each pane. Part of the idea is that the glass should not touch the wood directly anywhere to minimize any flanking of vibration into the frame plus sealing it all airtight. In other words, neoprene on all three sides of the glass: face, edge, face.
I ordered neoprene from a local shop custom with sticky on one side. Installing is not hard. Glass installers should have the hard setting blocks with them. Since glass is a commodity, the lami has come down in price for me.....