Whichever you shoot best. In the long run developing the mosin into a better hunting rifle would be smarter than the AK. You can get a sporter stock for it and such without damaging the rifle.
THe key on this trip will be to limit the range you shoot at. If you hit a 5 inch target at 50 yards that is all the farther you should shoot with either gun.
The first few times I went hunting I just tried to learn as much as I could. Work on the riflery a bit before next year and just be happy to get out in the woods this year.
Of course, all but one of the shots I have taken have all been within 50 yards.