You can put one into a tub set up to save money until you can have two full elaborate set-ups. A tub is also very easy to keep humidty up properly in. That way you can seperate them right away, while not having to buy a whole new set-up.
Walmart sells a nice little temp/humidty sensor for about $14. It's in the indoor/outdoor section with the outdoor thermometers.
Good luck, and congrats on your new pets.