Hi! LinkedIn is the best place to find people for all profiles. I have used it to find some sales professional myself.

You could use Reflik too if you want to outsource recruitment.

Try searching for candidates who are already familiar with the profile and industry that you are looking for.

I am not sure who is recruiting in your organisation but a sales role requires a lot of patience and research and just outsourcing might not help. You may need to dedicate a resource to find the right person.