My Galen Rowell bags open from the body side out. Galen helped develop them and I guess hanging from the side of a mountain by one hand, he wanted a bag he could get into. RIP Galen.
I will only buy camera bags that are top loading backpacks. I will not even waste my time to look at the popular dump my camera on the ground style backpack.
It works great for an OM body, but medium format or 35mm with built in winder bodies are wider/deeper than is optimum for the compartments under the zippered flap.
I have an athletic/gym bags with the same sort of closure and better room inside, but it lacks the dividers and padding I want.
And of course, as I am left handed, the double zipper zips in the wrong direction :(.
Years ago, I had one shoulder camera bag that opened the way the OP described and the top served as a stable level tray. I could never find another one like that.
Benji I have the same problem, must be those right handed bags we're having to use. On an unrelated note being a lefty has at least one advantage , if you're not keen on loaning something just tell them it's left-handed:) .Most people then look confused and decide they don't really want to borrow it. I usually wear the bag "backwards" if I'll be in and out of it frequently.