I suggest you take the plunge and go for a large format 5x4 camera with an international back. They are not too heavy, versatile, and with one you can learn to focus on the key elements that make an interesting image. They are completely un-idiot proofed but flexible (except for sports photography ). You can use them with roll-film backs which are available in various sizes: 6x7cm, 6x9cm and the panoramic 6x12cm, as well as 5x4 inch sheet film. If you bought a 5x7 inch large format camera you could also use it with a 5x4 reducing back (enabling you to use the international roll film backs) and you would also be able to use a motorised 6x17cm roll film back too.
Walker cameras do an affordable 5x7 inch camera, if you are interested.