Southern Style Offroad also has a slim line bumper.
2014+ 4Runner Slimline Hybrid front bumper – CUSTOMIZE YOUR OWN – Southern Style OffRoad
Trail 4runner did a pretty good write up as well:
5th Gen 4Runner Front Bumpers, Full-Length & Low Profile Bumper List
[MENTION=121817]Hydguy[/MENTION] is spot on with the recommendations.
If you start adding weight you'll need to research options for suspensions and coil upgrades.
Although to note, there are a number of folks on this forum who did a small lift, 5100s and used stock coils and then added a slim bumper. The performance hit was small, but noticeable when braking, slight nose dip and more compression due to the added weight. In the end it all depends on what you get and how much you add to the front end.
Based on your comments thus far an aluminum bumper is probably what you're after. It's more expensive, but the weight savings can be a difference maker.
Just for context I have the full skid plate aluminum option from RCI (including gas tank and lower link arms) and have come down super hard on rocks and the aluminum did gouge out, but no cracks and no major damage. So even giving up some protection vs steel, aluminum will still hold up well if you bash it a bit.