If it's primarily a daily driver, even in snow and ice, and it will only occasionally be used off-road, I'd think 3.73 gears would be fine with those 31" tires. If you're going to do a fair amount of off-roading and not a lot of freeway driving, then 4.10 gears would probably be the better choice.
If you're going to drive on ice a lot, I'd suggest opting for a selectible locker, rather than an auto locker. Auto lockers can sometimes get you going sideways on ice, especially on off-camber roads.
1977 CJ7, AMC360 V8 w/ headers, DUI HEI, Edelbrock intake, Holley 4150 carb, , TF999, D300, D30 front and AMC20 rear with 4.56 gears and lockers both ends, 4" susp lift, 2.5" body lift, 35" BFGs, ARG steering, 8000-lb winch, etc.