There aren't really any GOOD aftermarket replacement assemblies. They will likely be worse than what you have, unless of course your current headlights are fogged up. I'd start with polishing them good and applying a coat of wax.
The only real option you have is performing an HID projector retrofit into the existing housing. Mini D2S 4.0 is a great option available from theretrofitsource.
There are people who will do all this for you, but the cost is pretty extensive. If you do it yourself you could do it for under $300.
No aftermarket bulb swap is going to give you any real performance increase, and aftermarket bulbs like just a simple HID bulb kit for your truck is just going to cause a whole lot of glare and foreground lighting. If you're going to go HID, do it right and swap in a proper HID lighting element into your housing like I suggested above.