If it's landscapes you want to shoot the suggestion for a 5x7 is a good one. Develop the film yourself and make your own contact prints. Plus the longer 7" dimension is an asset, IMHO for landscapes. Be aware that film holders will be more costly as will 5x7 film when compared to 4x5, but you can always put a 4x5 back on a 5x7 camera if it gets to be too much.