Projectors HID vs. Halogen

Are the projectors with halogen bulbs the same as projectors with HID bulbs? Is the spread the same and everything or do I have to buy a special kind of projector to house an HID system.

I know that both bulbs are h7's but I do not know if the heat difference has an effect on the type of projector you need.

Thanks.

any projector should be able to fit aftermarket HID. 

thanks

True HID projectors usually come with D2S or D2R Xenon bulbs that are specifically designed only for HID projectors.  The H7's are a halogen projector bulb.  The HID "Kits" are a psuedo way of achieving near oem Xenon quality lighting at a fraction of the cost.  In simple terms, they are simply taking a Xenon bulb and rebasing it from a D2R/D2S type to an H7 type.  Being a xenon type bulb, they require the ballast/igniter combo to be driven.  Therefore your basic HID Kit will have the new (rebased) H7 Xenon bulbs along with it's associated ballast/igniter, wiring and mounting brackets that can be done easily as a DIY.
HID Planet is a good source for research on this.