There are a lot of Middle Format (MF) cameras that don't use Waist Level Finders (WLF), such as Bronica RF645, Pentax 67, etc., so there is enough choice for alternatives.
With my WLF cameras, like my Bronica SQ-B or Rolleiflex T2, I don't mind composing without a prism finder. I even like composing this way.
Left-and-right-reversed focusing is (at first) getting used to, but when you do, it might even help improve your composition. It makes you more aware and think about what your doing.
Tip: turn an image upside down to evaluate its composition.