A great bumper is the PARMA Ultimate Bumper #8049 $12.99.It is a very hard foam composite bumper. PARMA makes one for the TC4 and it fits the TC5 great. You only have to make two small cut outs at the top for the top brace,about a 1/4x1/8 in. And if you run rubber tires you will have to shave it for tire clearance,but it's still plenty strong.
IT SAVES ALOT OF PARTS!