@sfmmfreak: Of course snake necks have long necks. But as I said before, there is no problem with keeping them in a 90 gallon tank. I do keep some species with pretty long necks and out of experience I can tell you that there is nothing to worry about as long as you keep one or two and not more in this tank.
If the tank is nearly filled with water and equipped with an outside the tank basking area everything should be fine.