Colossus by East West is the largest GM soundset to date. But I think it didn't do as well as they thought it would. Only people into serious softsampling will spend that kind of money on a library - and believe me, there's many more things we will want to with that money rather than GM sounds! People who wants to try out GM sounds will never spend that kind of money - much cheaper to get a JV1010. 32GB of GM sound is just plain silly - I now have close to 100GB of samples; I will be crazy if a third of that is just GM. I can spend less money on dedicated sounds with better quality - may not get the entire GM template (I don't use more than half the GM sounds regularly anyway) but will sound much better with more articulations etc.
The thing with GM is about playback - so standard midi files can be played. But if we want to compose and write music with softsynths/softsamplers we should focus and invest on only the sounds we usually use/need. Eg - I never use the Shamisen, any of the guitars, the sound of the bird or gunshot and many other sounds etc etc in GM. Why pay so much money for that??
Anyway, since you already use the JV1080 from your church, just keep using that. I would try lowjk's idea about free soundfonts. If you really want GM sounds in software form, don't pay more than the virtual soundcanvas.
