Well,
How much do you know about the hunt you plan.
If you will be going for whitetails at less than 100 yards, you already have a rifle.
In Wisconsin the SKS's have been used very successfully for shortrange deer hunt (< 100 yards). (be sure to get ammo legal for hunting. For example, Wisconsin doesn't allow FMJ for hunting. PSP are available in 7.62X39, and others are around.)
Are you planning on one rifle to take anything up to a moose? If so see the larger bores as suggested. (someone has H&H .357 Magnum listed, I think he means H&H .375 ...)
I bought a rifle with the criteria that it must be enough for my first Elk Hunt. I found a used .30-06 and have taken 4 deer with 5 shots in the woods. I have MANY more shots at the range with it (more than 200 in 4 years). But first I was loaned a rifle (in .35 remington) and was able to use my limited experience the first two years I went to figure out what *I* thought i needed. Almost everyone else in camp was shooting .30-06. I said there we go.
Above .308 class cartridges I believe practice is more important than caliber. (FOR DEER) You need to talk to the buddy who invited you, you need to know LONGEST shot ever taken in camp, and AVERAGE shot length. If you are sitting in thick woods where you cannot see 150 yards, you aren't going to need Mr Magnum boomer, of course that isn't saying you don't WANT one. A trip with your SKS or a Borrowed rifle may solve your problems. If you sit there in an open field and see a deer at 400 yards and you have an SKS you are going to be sorry.
to summarize...
How long is you shot likely to be?
really really long or short in the brush?
How big is the game you intend to pursue with this rifle.
If it is only deer sized why buy another
rifle?
If you do buy I suggest PRACTICE practice practice so you know you can shoot it well from field positions. (no benchrest in the woods!)
As always IMHO and YMMV.
Good luck!
Gfrey