For an early retirement withdraw, should i pick eligible emergency expense OR separation from service after age 55, if both apply? Does it matter which one I pick?

[DoninGA]

If you separated from your employer at age 55 or older, then you would not be subject to the 10% early distribution penalty.  Box 7 of the Form 1099-R would have a code of 2—Early distribution, exception applies (under age 59½).