Told my old man I want a brush guard for Father's Day.
Brush-guards have a natural pivot point under the front bumper. That does a couple thing for:
1) Reduce ground clearance under the bumper (one of your concerns).
2) Because it protrudes in front of the bumper, you decrease the approach angle.
3) In a front collision, the brush-guard will pivot back towards the vehicle and like a jaw biting down, it will crunch the bumper, grille and radiator more than if the impact was absorbed by the bumper.
Based on the above and your concern about ground clearance, you may want to look into an ARB or Shrockworks bumper instead.
Okki