It depends on your rooms temperature. if you are worried about the 75 watt bulb not being enough, it comes in a 100 watt version. I would recommend that you get a lamp dimmer like this one to dial it down if need be.
http://www.google.com/products/catal...MAI#ps-sellers
The Infrared bulbs are different from other "night" bulbs. most are regular light bulbs with a blue or red coating over the glass. Infrared bulbs actually put out a different wavelength of light that is more effective at transmitting heat. The other main type of "night" bulbs are blacklights aka UV. Blacklights are at the opposite side of the visual spectrum of light and are very poor at transmitting heat. (Infrared light has a very large wavelength in which it can transmit heat while UV has a very small wavelength that reduces the amount of heat that can be transferred)
Sorry for the physics lesson lol