Depends on what your doing, if you are in a fabshop mode then once you decide Grade 3,5, 8 SAE or Metric Fine/standard then it really is a matter of how much you want to spend USA, Canada, Europe, Taiwan, China made product. The sky is the limit really for hardware
I would stay away from assortments as you will always get something you will never use, or not enough of what you will use the most of. Start with bins of sizes you know you will need and build from there. Buy good quality it will pay off in the end.
Ill PM you my contact but he is local he might be able to give you some leads.