Sigh... What a difficult situation to be in CJD. I'm sorry GS needs this kind of help, but glad he has you to turn to.
It sounds as if you are not totally willing, though, as you say you've been "told (you) have to." Do you not want him to come live w/ you? Or do you just not want to go through the process of becoming a foster carer? I'm sorry there was such short notice about the panel, but I hope you have found a way to work it out.
While I haven't been through this process, I have a friend who was, and I know that the panel is part of it. Annoying, I suppose, but worth it if you want to help GS and this is the only way.
As for the 3 weeks you have to wait for a decision, that doesn't surprise me. Court cases always seem to be long and drawn out. In fact, my friend was told about 3 weeks, and then it ended up taking longer b/c of some scheduling conflict the judge had. I know you would just like to have this over with and have GS moved in w/ you. But please be prepared for the fact that it may be a longer, more drawn out process than that. And rest assured, this isn't unusual.
Also I agree w/ Iam64 about legal representation, and I hope you have secured that. Please let us know how things are going.