Diamondback, out of San Francisco.
They have a set that's incredibly well designed for electricians. Pocket for Wiggy, pouches for wirenuts, just enough room for tools.
If I didn't have the D'backs, I'd try the new Klein bags.
I used to use leather, but I needed more space and I wanted more parts pouches than I could get with a leather tool pouch and a separate leather or nylon bag.
One set up that I haven't tried but looks good is a vest or shoulder yoke that tool pouches hang off of. Weight's off your waist. Made by Skillers, sold by duluth trading company. Find 'em on the web.
All $$$, but worth it.