IME what you'll find ebs and flows. Typically there is always something of almost everything. For example, I can recall a few times when it seemed like every 4th bag would be angelfish! A few other times I was pleasantly surprised at how many apistogramma varieties were present. Other times I've been disappointed by the number of malawians, though they are typically they represent well.
Whether there will be a "wide selection", sometimes yes and sometimes no. You won't know unless you come though!