Congrats to your buddy!
I'd try to make a trip into the Elkhorns during archery, the Breaks during the general season, and then hit up Gardiner in the late season.
If you have any experience elk hunting,there's really no reason you should need to hire a guide, but I'd maybe get in contact with the Martins at Flying Diamond out of Livingston. They'd be a great last resort if your buddy still has his tag at the end of January. The prices for outfitters on the late hunt are dirt cheap, and having one as a fallback could take some of the pressure off of connecting on your own. The late hunt has lots of really nice bulls, but probably not the number of really high end bulls as the other units.
The Elkhorns are by no means an easy hunt, but that's probably the area with the most potential for the biggest bulls.
Please keep us updated on the hunt, and pictures would be awesome.
I'm tired of always giving guys my input on this site and never hearing how the hunt went.