Keep in mind that Allen wrenches are wear items, not investments. Even good ones will have their sharp corners rounded after much use and should be replaced or cut down to remove the worn end. Small Allen wrenches (5 mm and below) are particularly wear prone but larger ones don't last forever either. A worn wrench is a sure recipe for damaged bolts.

Buy a new high quality wrench before installing the new bolts and, as noted, grease the threads to assure the torque does tighten the bolt, not just twist the bolt head.