What kind of snakes? Hopefully not Balls, or "A" Ball. And I also hope you weren't planning on housing any snakes together in that tank. I think a 70g anything would stress any Ball Python out, a 6ft boa, no, a 2ft Ball, definitely.

Sounds very interesting how you're going to put the door on, please take pictures if you can.

How were you going to heat something so big? Heating the air space alone is going to be an exercise in futility.