1st. Those lamps need to be on Thermostats- for now a hydrofarm like this will work just fine- http://www.amazon.com/Hydrofarm-MTPR.../dp/B000NZZG3S
2nd. That humidity guage they sell at petsmart is horrible get an accurite with probe like http://www.amazon.com/Chaney-Instrum...ter+with+probe
3rd. Another Hide (i see you already know you need this)
4th. If you are going to keep him in a tank you will most likely need to have 2 water bowls to keep the humidity up.
5th. infrared temp gun you will need to check surface temps with a lamp to make sure it doesn't get to hot in certain spots that will burn him. (while testing my tank I found that one of his hides roof was reaching 98 degrees before I put him in it)
Also make note that when that bright spotlight is turned off at night if the temps drop. Which it most likely will you will need to replace that with a red bulb.
Honestly I started with a Tank and after having it setup for a week decided I didn't like the idea's of the lamps. I never knew if my cat would get up there and knock them off, starting a fire etc. I ended up going with a Full plastic cage from Animal Plastics, using flexwatt and a RHP(radiant heat panel).
But now that I am moving into a much smaller place I am considering going with a 3tub fully enclosed rack. Which will take up much less room and allow me to keep 2 more snakes.
Any paper will work, its just to black out the walls. Make the entire cage feel safer.
And no the snake mites will not effect your cat. Only other reptiles.
NOTE* also if your worried about the lamps you can read up on here about how to make a tub cage using flexwatt. Its probably the cheapest method but can be a disaster if you let the room get cold during the winter. And if your really handy you can build a single tub enclosed box/rack thing.