Solisimo, the question you need to answer is where will you mount the ballasts for the HIDs. I'm not sure how much room you may have inside of the lights themselves, but you need to find a spot that is roughly 3x3x1" in size to place the ballasts. Keep in mind that you have to keep the ballasts within about 18" of the light bulb itself, so, that may limit your options.
As for the HIDs, if you are after maximum light, then you definitely want the 4300K bulbs. They are the brightest of all the HID colors for a given wattage. As for wattage, I would tell you to go with 50W HID setups mainly due to the availability of these setups. There are a few 80W HID kits out there, but they are harder to find and generally are at top dollar prices. Also keep in mind that if you go with the 80W HID bulbs, they will each need their own 30A relay due to the starting surge (around 40 amps for each bulb). Once the bulb is up and running, then the running current will be down around 8-10 amps. But that starting surge is big and can damage relays and whatnot. Atleast with the 50W bulbs, you can pair up the lights and run them off of a 40 amp relay (so only 2 relays would be needed).
As for light, the 50W HID bulbs are going to output about 4 times the light of a 55W halogen bulb. So, when it comes to light, you will have plenty with the 50W bulbs. The Pro Comp housings as I recall (double check me on this) are rated for up to a 100 W halogen bulb, so, the housing will handle the heat from either the 50W or 80W HID bulb. As for mounting the bulb itself, this is where you need to know the bulb style (normally an H1 style), then all you do is find an HID kit that has a bulb in it that matches the H1 style. Then it is a plug and play setup.
Like I mentioned, if you have more questions, I will attempt to give you the answers that you are after.
