For the stuff you are looking to buy, I would assume an automotive repair kit, if anyone has one, would have some sort of jack with it. It is not a major lift though. Not a nascar type jack (I feel dirty saying that) or anything like that. More or less what you would have in the trunk of your standard SUV for changing a tire. So if that works for what you want, you don't have to buy one seperate from a kit. If you want something sturdier, then you will want another one (since I'm not sure what you picture when you say hydraulic, since there are a wide range of such).
Also, I'd let you assume you already have one spare with your truck, of the same type you are driving with now. I'm willing to let you run it where you had some heavier duty tires already given the location we are in, but if you want some major off road tires for potentially crossing rivers or such, then you might need heavier tires. Basically, I know its not designed as an off road vehicle, but I would assume it is equipped to handle dirt roads in various states of repair as is, and savanna type terrain, but anything overly rocky or uneven you will struggle with.
Also, if you are hauling most of their gear, you probably want a tarp at least to cover the back end.
Also, since some of you have been talking about what you may need to buy. For survival kits, lets assume they include tents that sleep as many as two (in theory they might be singles but two works well enough), a survival blanket, three flares, a flint, matches (just assume an unlimited supply unless you really want to abuse them because they aren't worth counting), a water purification system that will deal with most chemical and biological agents (I say system, because again, its not worth tracking tabs), 1 pot (2.5 liters), 1 multi utinsil, a compass, one set of rain gear, a 1 liter canteen, 1 pair of gloves, 1 set of extra shoe laces, 5 sealing 5L plastic bags, 3 sealing 25L plastic bags, duct tape, 10m of fishing line with 10 hooks, 20m of rope, and a small hatchet (don't try to use it in combat). Anything else you think should really be included? I'd include food, but it needs constant replacing as you go through it. So if you have one, assume it has a 3 day supply of preserved food for one person, but that will need replacing as it's used, so you may want to just buy what you need ahead of time.)