Photography Bag Recommendation?

I've been looking for a bag to carry my photography stuff for some time now and haven't been able to find exactly what I'm looking for, so I'm coming to you for recommendations. Here's what I want for my photo walk-abouts:

--A messenger-style bag. No backback or bags that look like an insulated lunchbox.
--To be able to e-a-s-i-l-y reach into the bag to grab my equipment.
--Space for one DLSR body, one 35mm body, one medium format camera, 3-4 lenses, film, and a notebook.

Does anyone have experience using the Shootsac? It meets two of my three requirements, but when I see pictures of it on a person the strap seems way too short (I'm 5'9").