If you don't mind waiting, get a selectable like ARB. You'll like the ability to drive around on the street like a stock open diff jeep, then push a button and be locked. Geting something good like a detroit, ARB, OX, ETC... All require you to re-setup the gears. SO if you are regearing with the new tires and are going to wait for a good locker, get the locker and gears at the same time and kill 2 birds with 1 stone. If you plan on a lunch box locker like a lock right or aussie, you can install one at any time in the driveway.