I would suggest not getting any neons with a Betta. In the summer I got 5 glowlight Tetras and my Betta, Pigg, literally ate them all after the course of a few weeks. I didn't even notice they were missing until it was too late. My friend had also at that point decided to get some Neons to go in with her Betta (she got 7, had a larger than I did) and had to return them after her Betta killed 2. It could just be our fish (hers died a few weeks ago, he was about three), but my Betta gets along fine with my Otos and my Mystery Snail, so they may have just been too flashy.
55 Gallon: Crowley: Melanoid Axolotl; Mischa: Melanoid Axolotl; Achlys: Albino Axolotl; Eddard Stark: Leucistic Axolotl
Furry Friends: Daisy and Holly: Dogs; Norman and August: Cats; Gilbert and Mordecai: Guinea Pigs