Is this a good stocking for my 16 gallon freshwater tank?

I have a similar sized tank. I have none of those fish but whilst researching which fish i was going to get i looked up all of these fish in lots of detail. I think that is perfect stocking level. I have some peppered Corie's. They are fantastic little catfish. Each have their own personality and they are such a joy. Also, they are slightly smaller than otos i think. So i would say go for the Corie's you will not be disappointed!! The other issue i would like to raise is with the guppies. The males do look lovely but they do not like to live alone but if they live in groups there must be females present or the males will fight. Usually it is 2 females to every male. You have room for that amount of guppies so i would go for that option so they are happy. And remember that it may take a while but don't rush the stocking of fish. It will pay off in the end. Please let me know in your reply what you have chosen to do i would love to know.