I actually followed the instructions from this site:
http://users.skynet.be/fhoes/rsasucculents/sowing.htm
Lithops are not hard to sow and germinate at all. They basically just need to be kept damp and given some light in order to germinate. It's keeping them alive afterwards that's the challenge.
This site has excellent care information, although it's not aimed specifically at tropical climates
http://www.lithops.info/
Another good site is
http://www.lithops.co.za/cultivation/cultivation.html
I would assume you'd want to water them less, since they'd be getting some water just from the humidity in the air, and I'm not sure what you'd do to give them seasons, I suspect they wouldn't thrive (and certainly wouldn't flower) without seasons.