....do you have any fabrication experience?
no offense but it really doesn't sound like it or i don't understand your question really....
on "how to fabricate a off road bumper" you typically spend alot of time with a tape measure and cardboard making various sorts of mock ups to get the look and profile you're after, from there you swear,cuss,drink, smash fingers and toss metal until you have something you are happy with...
or are you simply looking for ideas/picture of the various bumpers out there to get an idea of what you want to make?
really confused by the wording here.