What you may have heard about control arms breaking is not actually caused by the spindles. Sometimes when running 3" spindles with smaller rims or even deep backspace on larger rims the back of the rim will hit the control arm. To eliminate this problem people grind the lip of the control arm away. This can create a stress point and cause failure of the control arm.
If your going to lower it and can't afford to bag it then go with a 5/7 drop. If you go 4/6 your goinng to want more later. You may as well do it one time and be done with it.....
