First off might I suggest a 642. I have a 642 and would recommend a stainless if you want to carry, just one less thing you have to worry about. And I have a 642 with the "Hillary Hole", thought it would be the end of the world at first but it isn't a big deal. If you ever want to lock the gun then you have the option, but I prefer to lock my entire gun in a safe instead of internally locking it. The only difference between these guns is one can be locked with a little key to keep the trigger from moving.