Welcome to the neighborhood!
I have never put the halos on one myself and some look good, but there are cheaper ones that look like crap. As for the HID's, DDM Tuning offers kits for your truck that you can replace the headlights, fogs, daytime running lights and high beams all at once, as well as the marker lights. An entire set up may cost in the neighborhood of about $250-300 for the HID bulbs with the ballasts.
Other possible mods that many folks do to theirs include but are not limited to;
Headers, high flow catalytic converters, high flow cat back exhaust, cold air intake, lift or lowering kits, rims and tires (obviously...lol) and aftermarket tuning whether they get a simple "CAN" style tuner like an Edge Evolution CS/CTS or go for the gusto with a Black Bear Tuning EFI Live custom tune. The list goes on and on and on with what you can do...lol
I am a site vendor and am here to help and offer support before AND after the sale, etc. If I can be of any assistance with your upgrades in the future please feel free to shoot me a private message right here on the forum and I will be glad to help you find the information and parts you need...