The general rule of thumb is about 4W to 5W/gallon for most rooms.
Here's a more detailed decription:
http://www.beananimal.com/articles/a...-to-know!.aspx
Titanium heaters work the same as glass ones. They're simply less likely to be damaged because they're not made out of glass. Plus it's cool to say that you've got a TITANTIUM piece of equipment.
They are still subject to sticking like glass heaters so a good quality external controller is the safest bet if you will be keeping very valuable livestock.