You get the bolt in kit which provides the projector, brackets and hardware at minimum. Additional things you should purchase would be the butyl sealing rope (sold at the same place as the kit) and to make your life easier get the permaseal remover stuff that eats it. You bake the headlight at like 270*F for 10 min or so and pry off the lense of headlight... might and will take a few reheats (less time as its up to temp) untill you get it off. Then unbolt the stock projector and bolt in the new projector with bracket. Clean up the channel around the headlight and apply the butyl rope sealant in the channel. Heat it up in the oven and press the lense back on. Thats basically it and this is the downplaying how much work it is description. Took me about 4 hrs I think to do it fully start to finish but this was before they had the permaseal eating stuff they sell in a can. Permaseal is permanent sealant and its a HUGE PITA to get undone once its cured. The good news is the butyl will be easier to heat and remove the lense if you need to down the road for repairs or to swap out the turn signal board. If your planning to do switch backs or something in the OE turnsignals now is the time when you got it apart the 1st time lol. Hardest part is getting the lense off without breaking it and getting the old sealant out.
ALFOOBD has settings for HID and LED for the headlights/fogs/highs so you can change it and probably you wont need a relay harnesses, decoders, resistors and all that jazz. Would make a huge difference in work and some cost if it worked. I've heard it does and sometimes doesn't always work... depends on the vehicle and the system/brand gear your running. I would say a 35w HID kit would work fine with the factory wiring as the amp pull is lower or about as much as stock. But a 50w+ HID would require upgraded wiring and thats why I like the HID harness. You could still run the harness and program for HID/LED and just let the relay harness carry the load perhaps. A good 50w HID will pull 5+ amps on startup but mellow out to around 4 amps running.
FXR 3.0 is just the type of projector... its a FXR, 3.0 is the lense size they also have a 2.5" lense size. Looks like kit costs have gone up lol but $600 gets you everything you need these days, D2S 5.0 projectors, brackets, HID harness, sealant... all you need is the permaseal remover. If anything the D2S 5.0 projector is on part with the FXR 3.0 and probably has a better hot spot.
https://www.theretrofitsource.com/2013-2018-ram-projector-upgrade-headlight-package?quantity=1
Permaseal eater:
https://www.theretrofitsource.com/morimoto-permatrator-solution-for-permaseal-B-PERMA?quantity=1
FYI I see they have an option for there Bixenon LED projector retrofit... that would be pretty good too but your SOL if the LED's take a dump.