How should coveralls fit? Planning my first purchase ever

How should a coveralls fit?

I am planning on buying a coveralls. My chest is wider than my waist but every jumpsuit I find has these issues. My waist is 30-31 inches and my chest is 40-41 inches. I am constantly bodybuilding so I will pack on more muscle:

  • a medium sized coveralls will be exactly at 40 inches for chest and 32 inches for waist. The waist will fit perfectly but the chest will not give me much room to move.

  • a large sized coveralls will be at 42 inch chest size and a 36 waist size. The waist will be too loose but the chest will be just right.

How should j go about buying my coveralls?