Hi gadabout,
I use an Orvis chest pack that I sometimes use over my shoulder and sometimes as a fanny pack and sometimes as a chest pack. It depends on what I am doing and where I am fishing. It is my warmwater fishing kit as it is too hot to wear the vest. If I am rock hopping on the river I flip it around as a fanny pack. If I am just walking a bank and can see where I am going well enough, I will turn it around to the front of me or wear it as a chest pack. However, William Joseph makes one that I believe is called a bandolier and it is really nice with built-in pockets etc. All Wm Joseph is pricey but worth the money. I know that most reputable fly shops carry the William Joseph line of vests and packs but since I don't know your location, I suggest you start an online search or check your catalogs.
Good Luck in your search.
Gerri