but a N frame is a bit chunky for concealed carry.
There just ain't that much difference between the N frames and L frames. The cylinder is 1/8" thicker and 4" guns are 1 oz heavier if both are 6 shot guns. The 8 shot N frame 357's are lighter than the 6 shot 686's. They will often fit in the same holsters. If one is too heavy and chunky, so is the other.
Personally none of the above would be my first choice, but any could be an acceptable choice. Just get all the facts right and base your decisions on accurate information.
6 shots, vs 7, vs 8 shots is a decision you have to make. As well as how much you want to spend. While it isn't what I'd buy it sounds like a good choice for you.
I'm not overly concerned about S&W problems. They are a solid company who generally makes very good stuff, especially their revolvers, and will back it up if problems come up.