I like
this bag - I have an older version that I like a little better but the essentials are similar. Center area holds body plus medium sized lens. Sides hold a couple of smaller primes back to back each or one medium sized lens or a flash each. I've carried a very small tripod (table top variety) in one of the side pouches. I can put my 50-135 in a side pouch with the hood but it's very tight - without the hood it fits easily. The 60-250 also fits even with the foot but my foot is the DA* 300 foot which is smaller. Again the hood makes it a much tighter fit and you couldn't carry both as it encroaches into the space in the center a bit.
As for access - my center section has zippers as do the side pouches, I can leave the center unzippered and quickly grab the camera but it's not secured if I do that. I have an old Galen Rowell Photoflex bag that I use for speedy access but it only holds a camera and lens together. The case logic bag is nice because there is also room for a few minor accessories including spare batteries and cards. It is the bag I use when I don't need everything - when I need everything I'm carrying a Domke or the large Galen Rowell Photoflex bag. Frankly I am thinking I'm more of a backpack guy than a shoulder strap guy. I want to put the camera in hand or around my neck and only access the bag when changing items typically.
The problem with adding a tripod to the mix is bulk and weight distribution. With any bag that's quick access I think you end up with the bag on your shoulder or around your waist, and I'm not sure there is any way to add a tripod to that without making it harder on your back and or too encumbering to use. Maybe someone else will have ideas.
Another
version of the bag has a small single camera with lens travel pouch that packs inside it and lets you put the camera in that when you forage out for photos - not sure when that would work but the
video on amazon shows the main bag reasonably well and it seems like the same bag other than the small quick access camera pouch that he pulls out of it.
Something like
this may help the back... slower to access the equipment but should help the back a lot with the waist belt and strap connection to distribute the weight.
---------- Post added 01-29-15 at 09:44 AM ----------
I really started looking since you asked and your needs resonate with me.
This bag is a good compromise that does everything except the tripod.