Well, it's your choice of course. If you decide to buy him I would make sure the tank is very well planted so that the tetras have a repreive. If you do get a betta though, I would not get the snail or the otos. Although- do you have a tape measure? can you get the length depth and height of your tank? Did you determine the size in another thread? Because that bioload in a ten (a betta and five neons) isn't horrible, even if I wouldn't recommend it to a beginner. In an eight gallon I would really hesitate.