There's quite a lot of great info in regards to JDM conversions here. The hard part would be finding the bumpers, but if you can find a JDM importer who can get one shipped from Japan then it will be simple. I would offer to send some over from here, but the shipping price is about $700 alone. I can send smaller things such as the JDM grille, headlights and tail lights however
You should find this particular thread useful. It shows which JDM bumpers fit on your car, with little to no modification:
The JDM Corolla bumpers will fit straight on (although you'll have to remove your safety crash bars) but the JDM Sprinter or Levin bumpers will require modification. The AE101 FX-GT front bumper is a popular choice, and will fit straight on.