Yep, I do pull from the GMP. But for the GGGs, I mainly use the spreadsheet here:
docs.google.com
Which I think was getting maintained from the main GGG thread here:
forums.frontier.co.uk
Glowing Green Giants - The Definitive List
Which I think was getting maintained from the main GGG thread here:
Glowing Green Giants - The Definitive List
Most gas giants, even those which are classified as "life-bearing", are not particularly rare - about one system in ten seems to have a life-bearing one, with either "water-based life" or "ammonia-based life". They're so common that Universal Cartographics do not pay any premium for them at all...