Viper and Warn winches are going to be your best bet. If u only plan on using it to pull your buddies out (as the Grizzly rarely needs to be pulled out)

then going with a 2500 will be good enough. The comments above are both right on the money.
IF you are handy then I would suggest getting it and putting it on yourself. It"s not that hard to do and it get's you more familiar with your new Grizz and that is always a good thing.
How it breaks down is that the WARN is the Caddy of the winch world and Viper is more like a solid & reliable pickup truck.
THe WARN costs more but has a few more bells & wistles and is made well. You can get 2+ Vipers for the cost of a comparable WARN and still be able to count on it when things get ugly.
Good thing is that if you are a Grizzly Central Member, you get a discount on the Viper. You can pick up a 2500 with synch cord, delivered for $210, with the GC Discount. Add 10-15% without it.
As you will be doing more of pulling your buddies out of the mud instead of yourself, you may want to look around in here. THere are plenty of threads about mounts which allow u to switch the winch from front to back within 2 minutes. There are self reeling tow rope systems (TigerTail) and multiple other ideas which may interest you.
Stick around and look around. This is a GREAT site for us Grizz owners!
Best of luck to you