Like most everything else in pipe smoking, there aren't any simple answers as to what size bowl is best. It depends on your packing and puffing style, where and how long you like to smoke, and the tobaccos you favor. I mostly smoke Virginias or Virginia/Periques, indoors, and I rub out my flakes. I find mid-sized bowls (0.8" to 0.85") work best for that. But that's just me. Try to get a few different sizes as you're building up your collection and see what works for you.
As for differences between brands, all the ones you mentioned are first-rate, well-known brands. Many smokers develop a preference for a given brand's construction or briar (as well as style) over time, but if you're just starting out they're all equally fine. I'd just consider them for stylistic differences at the moment. As my first and wisest tobacconist told me long ago, "First, pick a pipe that looks good to you, because otherwise you won't smoke it." So like bowl sizes, pick a few brands that look good to you and see how they work out.
