You can still run HID lights in a regular light housing and it'll be fine as long as it's installed/aimed correctly, there's cars that come from the factory with HIDs but inside a reflector housing (first Gen G35, 5th gen maxima).
Of course a projector housing is ideal for HID lights, but retro-fitting the projector bulb onto a regular housing will take some work and you'll have to open up the housing, cut out a hole for the projector, break off the og mount for the bulb, mount the projector, reseal the case and hope it is still water tight.
DO NOT go cheap on HID light kits especially the ballasts, the best option is to get OEM projectors but they're not cheap unless you can find someone selling their old stock ones.
Used Audi A6 projectors for $250
http://hondamarketplace.com/showthread.php?t=2333903