May be your best bet to just surf the 4th gen picture thread or search for brush guard and see what threads pop up. edit - or just google image search 4th gen 4runner brush guard
There are only a few options and most don't look great. Because the grill opens with the hood, most lean out from the lights/grille and don't flow very well. There is one guard, either Aries or Manik I think, that actually fits like the way most other vehicles do. I'm not sure they even still make the one that fits right though.
Either way, there aren't a lot of members here with brush guards so you may not get a ton of replies. It seems like a lot of members who get them eventually ditch them.