??? Is there a huge diff. in the rental charge for some sort of an SUV?? I own an F150 ext cab 4x4 and I've done some traveling and moving with it! really, any half assed decent rope will work to hold down your gear, and a tarp will work fine for basic weather protection,.. Not Weather "Proof", but keep snow off!
My concern is, all that expensive gear and wrapped gifts are NOT going to be secure in a truck bed!! I'm talking potential thieves!!!
Since you went with a PU truck, I assume a "full cab" consists of 4 - maybe 5 guy's for this trip?? If the price isn't a huge departure, A decent sized SUV might be a better choice! You can tie larger luggage or boards & bags to roof, lock gift's & smaller gear & stuff in veh. when stopped for food/gas! Obviously not theft proof, but take more time & risk more attention to get at!
Oh and anything small(ish) or lightweight (like a small gift boxes) that aren't stored in something could possibly come loose & get blown up & out of a truck bed. Even out from under a tied tarp or cover! Seen it happen, had it happen!!
If you stick with the truck, Get a couple bundles of cheap, but decent 1/4 or 3/8 in. cotton clothesline rope. Avoid the nylon boat rope stuff. Harder to cut, frays apart completely when you do and unless you're a climber or know your knots, nylon slips & is harder to tie securely!!
You're only Young Once,.. but you can be Immature FOREVER!