Hi, Sandra! Your husband is going to find that Walt Disney World has many, many rides that he can experience. I can ride everything; however, Mission:Space and Big Thunder Mountain Railroad are the two trickiest for me. If there's ever a doubt, ask a Cast Member for information about the ride. I did this when Expedition Everest first opened. There is a trial ride car that I tried ahead of time. Okay, it is really to time those who need to transfer from a wheelchair to see if they can do it in the allotted amount of time, but the Cast Member let me try it on for size because I was so nervous. No problems!
Let me give you more information about how to access the WDW at Large portion of the AllEars website. It can answer so many questions about which rides have lap bars (the hardest ones to deal with for us big folks), theater seat sizes, how to best deal with those pesky (but essential) lap belts, etc.... First go to the AllEarsNet dot com website. From the banner at the top of the page, select Walt Disney World with the subcategory of Planning. Scroll way down the page until you find (in the left-hand column of links) Size Concerns: WDW at Large. Pretty much everything you could think of is there. That information had saved me countless hours of worry, so I hope you can find it now.
As always, if you have specific questions about specific rides, just send them my way!