Good luck with the Neons Sergio.
I have kept them in several tanks over the years. Normally they die, but my most recent trial with them proved very good.
Although, as Jaguar mentioned, I would go with a drip acclimation. I ran a 1/4" tube with a flow control valve on the end and let them acclimate for over an hour before I added them to the tank. Lost a few, but the neons are doing excellent.
Also, I read somewhere (I cannot find it for the life of me), of an experience where someone floated bags versus placing in a bucket and the fish seemed to do much worse when floated.
I have seen fish get quite worked up and frantic when floated as they can see a huge tank, but no way of getting in. Anyways, I no longer float bags.