If all you're shooting for is a championship, I'd say the choice is completely yours. Nice natural ears wont stop your dog from finishing. If the ears are full-prick, full-drop, etc., you might want to do them. If you were aiming for a top 10 dog, you would probably have an easier time with a cropped dog. But for a CH, having ears wont stop you. Me personally, I show my dogs at a handful of shows a year, but I have to live with them every day, so I make my decisions based on what I want, not what the show ring wants. I finished my dog with her ears intact, and some of the dogs she beat to get there were cropped. (Thankfully she keeps her ears a little more subdued in the ring, whereas they go waaaay up when we're out hiking with stimulus around.) It's only a small piece of the puzzle.
ETA: If you're going to crop, go with a nice show crop. The ears are typically 1"-1.5" long at maturity. A bad crop can detract from the dog's look. Some people prefer a short "battle" crop, but it doesn't necessarily "clean up" the head, and neither does a long crop like a boxer gets. Go to a vet that crops show dogs and ask to see their work.
UKC CH / ADBA CH Terra.