whats the different things you can do to them
You can shoot them.
1911 is one of, if not THE most customizeable pistol available. What CAN'T you do to them? On a 5" for example, starting at the muzzle end, you can customize, change or eliminate your bushing; you can go with GI, FL or 2 piece guide rod; any type of front sight you desire; front cocking serrations or no; French borders all around, lowered and/or flared ejection port; trigger guard checkering front strap checkering;
You know what, this would take all day to list. You can do anything you want to them.
whats the different things you can do to them
Buy a Kimber and wil need nothing, but maybe night sights...