I think with you mindset you'll do find. My main advice is don't get into a frenzy (not that you are now -- just don't start). Take it one day at a time. I agree with the comment that kids with physical disabilities are extremely resilient. I see nannies all the time with kids having a physical disability of one sort or another and it is -- like -- nothing.
There is exploding development in technology to aid the physically disabled. We cannot envision the amazing aids that will be available to your older child.
I'll second this. My niece was born with a limb deformity, heart condition, and some other issues. She's in a prestigious high school now of a full scholarship, is a star soccer player, and one of the nicest kids you'll ever meet. The first year, especially, was hard for my sister. There was lots of therapy, some surgeries, and some growth issues. By a year though, she was thriving, and it's all water under the bridge now. Good luck.