Instead of buying first, take the time to understand what you are doing.
In the other thread I posted the link to, included a link within to Daniel Stern's pages. There is very good reading there.
http://www.danielsternlighting.com/tech/tech.html
When it comes time to do anything to your truck start with the basics as we said in the other thread. Specifically grounds, wiring, connectors at the headlamp, head lamp switch and the dimmer switch.
Then once you are satisfied add in the relay kits, go quality.
After you have the relays then you can decide how much more you want to go. The great thing is incremented this way results in benefits and you can stop. Relays and cheap sealed beams are better than stock or deteriorated stock. Better sealed beams are the next step unless you want to jump directly to replaceable bulb headlamps.
Bottom line is learn before you spend. If you don't know anything about electrics get some help. Hoping an eBay bargin kit's instructions will solve all your problems is a bad start.