hand formed loaves will rise over the top of the pan, sometimes similar to the 'muffin top' effect as well.
If you wish to use a bread machine the shape of the pan makes a difference in the final loaf shape since many machines do multi size loaves. If I do the smallest loaf in my machine, it comes out vaguely rectangle shape but very flat looking, not at all like a normal loaf of bread. You'd have to slice it horizontally to get a big slice from it. If I make the biggest loaf in it, of course the pan size won't have changed but the bread is taller and looks more like what you'd expect a loaf to be.
To help bread rise, especially with lower gluten flours (not just your normal white loaf) adding vital wheat gluten makes a huge difference to how it will rise. I smuggled some back from the US on my last trip and other than the stress of having an unlabeled baggie of white powder in my suitcase, it was worth it.
