I know a lot of people are pushing 35mm, but have you looked at medium format?

Nice big film, nice big lens, nice bright viewfinder, or even hip level viewing. yes, they are big and heavy, and the film is hard to find (in a store on a shelf) and expensive but the results are great. As for focusing, I have a Pentax 6X7 with a metered prism that I shoot handheld and while I can focus it fairly easily, it takes me some dexterity to get the job done.

Just like everything else, as it gets harder to see, get a bigger one.