Hi disgoer!
Sounds like a great trip for your son! So glad he's doing well and that you can get away for two whole weeks! That alone, will truly be magical!!!
I know
Dreams Unlimited will put packages together for you but i've never used them so i'm not sure of the prices etc.
However, i would tell EVERY CM you talk to, before you go and while you are there, including and especially at POFQ. Call them directly now and just ask what they can do.....both free and for a price. I'm sure this has been done before and they likely have many ideas and will be very eager to help you celebrate your son's recovery.
As many others, we've been at WDW for our dd's b-day and also
Disneyland for mine, and they've gone waaaay out of their way doing little things to help us celebrate so i'm sure they'd love to help you celebrate your joy! When you call back to request specifics at your resort, be sure you tell them and they will make note of it. If you don't get a good response from the first CM, then wait awhile and call back. As in any business, much depends on the person you're dealing with.
Also, you might consider sending things ahead, or arriving before your son enters the room, and have some special treats and toys there for him. Thats part of what DU would do too i think, so you might be able to do it yourself in other locations also...??... i don't know, but it's worth a try.
Anyway, i just wanted to reply and wish you all the best to you and your son! Have a great time!!!