I used the bumper from this thing as template to create a new front and rear bumper. The rear bumper is lower to accommodate the battery wires.
I also created a top bumper that can be used both for front and rear.
I have the 6" arms so I used the arm bumpers from this thing. For 5" you can use these.
Print with 100% infill.
The insanely cool LED holder at the back can be downloaded here.