I would be cautious of dog groomers who offer nail clipping for rabbits. They may not know how to handle a rabbit and could do some damage without meaning to.
You could try contacting a breeder if there are some near you. A local rabbit or small animal group could help too. Even a good rabbit person may be willing to help you out. I know that some pet stores offer nail clipping services. A rabbit savvy vet should be able to do it for you too.
There are some groomers who will do rabbits, but there are not very many of them who know what they are doing.