I got in touch with the amazing people at CorgiAid, Inc. (http://www.corgiaid.org/cart) and they appear to have a cart that will fit Zacky. It he adjusts to it, it could really enhance his quality of life, as his DM progresses over the next few months.
Not so good:
yikes. For a good (not) laugh, check out the comments from the 'skeptics'.