atmasters, what you need is what is called a "relay harness". An example would be:
H1 H3 H7 H8 H9 H10 H11 9005 9006 HID Relay Kit Harness | eBay
You need this for your Ford as the factory wiring harness is not truely designed to handle the starting surge of 35W (not 50W, more on this later) HIDs. This pretty much makes installing the HIDs plug and play except for maybe a crimp here and there. I wish I was close to you as I could get the HIDs in to your truck in no time flat.
As for what HIDs you need, you have to answer 1 question: what color light are you wanting? As for the HIDs that you need, most HID kits are going to do what you are after. As for why I say that you need 35W HIDs. HIDs are a much more efficient light producer than a halogen bulb. A 4300K HID bulbs outputs 3300 lumen of light where a 55W halogen bulb only outputs 1300 lumen (roughly). So, you are getting over 2.5 times the light already. You go with 50W HIDs, now you are looking in the range of 4600 lumen (or over 4 times the light). Imagine someone driving at you with 4 sets of high beams on. Think you might be a little pissed at them. Well, you would be doing that to everyone you pass if you did the 50W HIDs for your low beams. If you want to do the 50W HIDs for your high beams, by all means. You shouldn't have the high beams on when you are passing someone anyways. Also keep in mind that the 35W HIDs are the only ones with the DOT stamp on them. So, they are legal to use (some states have varying laws, so, you need to know your local laws to verify 100% acceptance).
If you do use the 50W HIDs, make sure that the relay harness is rated for a 30 amp draw per bulb. the 35W HIDs only require a 20 amp draw per bulb.
If you have any additional questions, please let me know. As you can see, I know a little bit about HID bulbs and whatnot. Between working with security systems and getting training on various methods of lighting and using that lighting for security camera monitoring and having an extensive background in electronics/electrical, this is right up my alley.