Check out a great resource for just this kind of question: Boat Escape - Ultimate Oregon Boating, Camping & Fishing Resource |. Scroll all the way to the bottom of the page and look for "HandiAngler" on the left side of the page. They list quite a few fishing spots for the physically challenged.
Come back and let us know how you guys do,wherever you go. Good luck and have fun.
FS...I can take him to a lot of lakes, the problem for him is he can't walk the banks of rivers anymore due to weak legs and balance. He would love to catch steelhead or salmon over trout.
Next winter take him to the N.fork Nehalem fish hatchery on hwy 53. They have a great area for disabled folks, there are more winter steelhead caught from the ds area than anywhere on that river I think, lol.