It seems I missed your thread about buying the Bronica, but I wouldn’t have talked you out of it! When I first bought my SQA I did the two-format thing for awhile, but found the 35mm was only being used for a light meter. I even tried to wean myself of the format by including a 35mm rangefinder in my pack, now I have even stopped pretending. I am more than satisfied with my results and am even looking for more weight to add to the pack.
I have never really liked the harness systems of photopacks (though they may have improved, I haven’t tried one for a couple of years) and have always used a non-photo pack with a good support system, that I then modified. For me accessibility while I’m taking the photo is more important and I second Jeanette’s post POCKETS!
As for the 35mm format itself have you considered a 35mm back for the Bronica? This way you only have to carry one camera.