Is there anything I can do to make the paint more resiliant to paint chips? I really hate chipped paint on bumpers. Iv got the bumpers stripped, and prepped, just need to shoot them.

Using PPG singlestage paint.

check with your paint supplier, you may be able to add some flex agent like that used on fiberglass or plastic bumpers.

Get them sandblasted,shoot few coats of epoxy or etching primer. Or blast,then properly powdercoat them,then paint.

Blast, epoxy and use urethane. I've done quite a few that held up great this way.