GSD

My favorite, best capacity for what I have ( an X-T1, 5 lenses, Instax printer, Nissin i40 flash, vertical grip and accessories), most variable carry modes bag is my Think Tank Change Up.

Not knowing how many flash units you require at once or use, have you considered the Nissin i40 flash for Fuji X? I used to have the Nikon system too, but sold it all and went with the Fuji X system. I considered other flash ideas, but found the Nissin i40 to be more than adequate, either as a slave, a manual flash or with a cord attachment to retain TTL metering. Additional Nissin i40 units can be slaved to the one designated as the controller flash. I would be interested in Fuji's new TTL flash when it finally becomes available to see what features it will have, but for now I find no fault with the Nissin i40 flash unit.

I have tried several bags including the Think Tank Retrospective 7, Retrospective 5, the Hubba Hubba Hiney and have found my old reliable the Think Tank Change Up to be the best at carrying the most, with the most carry options in a rather compact size. http://www.thinktankphoto.com/categories/shoulder-camera-bags/change-up.aspx It will hold an X-T1, 50-140mm, 35mm, 56mm, 14mm, 18-55mm, Instax printer, an i40, vertical grip, extra batteries, SD cards, lens cleaning stuff, filters, etc. I find it to be the best carry solution for all the listed items.The Change Up has the most and best carrying options of any other bag; two shoulder straps for double or single use, a waist belt with attachment points for additional Think Tank accessory bags if the need arises, front chest carry, side carry, plenty of pockets inside and outside for small items, a water resistant cover and internal removeable dividers. I sold the Retrospective 7 and use the Change Up for the X-T1 system. I use the Retrospective 5 or Hubba Hubba Hiney for my X100T. The Think Tank Change Up is like no other bag I have ever found. It is just too darn versatile. It doesn't have the "elitism" name or price tag some fancy leather messenger or shoulder bags have, but I really like the ability to carry it so many different ways with all the items. The "double across the back" shoulder strap option takes weight off one shoulder and allows me to use both hands for something else (like changing a lens or loading an SD card or battery, etc.) without trying to keep a single shoulder strap on my shoulder while doing something. By using the doubled strap option, the bag is in front of me and allows complete access to all my equipment where I can see it, not to mention it also makes getting on and off transportation vehicles easier with the bag in front of me. I'm not hitting other people or objects like it would if the bag were hanging off one shoulder. If I am out for a short time the single shoulder strap option works well. One can also remove both shoulder straps and use the compact carry handle sown onto the top back of the Change Up. I stow the unused shoulder strap(s) in the side pocket(s) and tuck the waist belt into its pocket in the back of the Change Up making for a compact carry handle style bag. The Fuji 50-140mm stands upright off the X-T1 body in one end of the bag while the three other lenses sit on top of one another with a wrap around them and the X-T1 has either the 35, 56, 18-55 or 14 lens mounted on it when sitting in the bag on the X-T1 on end with the lens facing toward the front of the Change Up. I'm not looking for another bag. (Another "Pro" for the Change Up besides carrying so much in so many ways is that I can't cram any more glass into the bag which forces me to quit buying more glass and saving money . The Change Up will not hold an X-T1 with the 50-140 mounted, but it does so much more than any other bag I have owned. (Which have been far too many )