Go price some quality (not the harbor freight or kragen specials) HIDs. I don't think I've seen a Hella HID light for less than $600, and we run 6 of those - 4 on the roof and 2 up front and we still want more light. You can get more light for less overall $$ with the LED. They only seem expensive until you compare them to an equivalent light source.
http://www.realtruck.com/hella_rallye_4000_xenon_hid_driving_lights/R141407P1C1T.html
Our plan is to run a single 50" on top (which is more light output than 5 HID), a 20" amber on the front for cutting through dust, and a 4" with a flood pattern in each headlight bucket. It is going to cut our power load for lighting from over 100 amps (HID draw between 15a and 20a each) to about 60 amps. That takes a huge load off the alternator. Plus we are saving about 50lbs (most at roof level), and we are going to have more usable light than we had before.
You would be amazed at the output of these lights. Two 4" on your roof will give you better light than 4 KC Daylighters. And they only take a fraction of the power.
And you need to see the testing videos on youtube. Search for Rigid Ballistic testing. The durability test should be up there too. A HID could not take any of that abuse (shoot a HID with a rifle and see if it still works...).