Actually thinking of the removable magazine. Should not be a prime consideration to ruling out a rifle that to you is the best choice. If you are going to have 2 or 3 of the same rifle in the same caliber, then having a extra mag or two, that work in all rifles is a small investment.
Considering the pounding these are likely to take, your investment in kit for the business is simply a tax write off, and consider the rifles to be 2 or 3 years then need replacing. Maybe you could get them prettied up every 2 years, but considering fat old clients and mountains, there might not be enough rifle left after 2 years to bother.