i have the full protek system on mine and i will say the oil pan is a huge MUST while the others are 100% necessary after 4 days in moab i have some good scrapes in my crossmember skid not to say the stock ones wont do the job but it is nice having the piece of mind that when i scrape the bottom on some of the steep climbs and descents that everything under there is protected is nice. my tranny skid still looks pretty much brand new but i also have a manual so its a bit more tucked up in there
this is what i oil pan looked like before i decided to finally put skids on and it looks like i caught it just in time before i did some serious damage to it
i also picked up this off of northridge and judging by all the scrapes on it after moab it was a good investment
it sits right up under the rear diff and came in handy when dragging the diff over rocks