Well a lot of good stuff was posted already.... Finding a bumper with the right shapes will be fun..
Once you get the chrome off you can cut and weld what you want to add or take out... The good thing is... It's heavy steel,, Easier to weld and work with... I would just build what ever shapes you want to add in... finding a bumper with the right shapes will make it easier,,,
The bumper is really no different then doing custom metal work on the body,, Just different thickness.. I would take in all the stuff that was posted in make what you want... It's really pretty easy once the chrome is off...Take your time and plan it out..
Just remember that if your going to rechrome it,, You will need to get everything as close as you can,, (look's that is).. If not the chrome shop will hit you hard....
Take your time,, And While your building it,, Keep thinking of it as art work and it will come out nice..
If you need anything else, I will do what I can to help you out,, If it was here we would already be done..