I bought a set of Primos Trigger Sticks for my son's recent hog hunt, then left them at home. The guide had a pair of 24" dowels held together with a piece of inner tube, and my kid used them to make a perfect shot at just over 100 yards. I have no doubt that they would have worked just as well on a far longer poke.
I'm a big fan of the sling because it works for carrying the rifle and for shooting it. A lot of folks confuse the hasty sling and an actual shooting sling--they're two very different things. Jeff Cooper's book The Art of the Rifle goes into how to use a sling at great length, but he focuses on the Ching sling. The Brownell's Latigo also works for a shooting sling, and doesn't require adding a third stud to your rifle, so it's the one I prefer.
If you carry a day pack, that's a pretty good rest if you're shooting from prone. Just practice with it (or with any other shooting aid) before you leave. It can take a surprising amount of fiddling around to get comfortable with any of them, but the results are definitely worth it.
Okie John