...can I just throw a halogen bulb in there or do I need up upgrade the entire housing etc due to higher temps?

 

Get a sylvania silverstar h4st or 9003. You hsould be able to just put it in. If you wnat to go to a higher wattage you might want to upgrade the actual plug for the light with a heat proof one as people have had the connectors melt with high wattage bulbs. Here is a link for one. http://easternbeaver.com/Main/Elec__...onnectors.html

I run the silverstar and it is fine, with the exception that the bright white ones burn out relatively quickly in my experience.

 

Go for silverstar H4, much brighter than stock, I don't even need high beam.