Hi! You should really take the neon tetras of your stocking list. Neons need at least a 10 gallon tank as they need more swimming space.And the betta would probably attack and possibly kill the neons too!Other than that I think you should be fine.
Still,neons need a bigger tank of at least ten gallons.And the betta living with the neons would be stressed and will attack the neons.However,it mostly depends on the personality of your betta. I personally would not recommend putting in the neon tetras.Also if the betta you got is calm, the neons tetras will be stressed cause a 7 gallon tank is too small for them.