If your bounty campaign is paid by token with real value, You can ask for Hhampuz and Yahoo management service because they are expert on campaign management. But if you are planning to pay bounty hunters using token that no assured value after the campaign is over then don't expect that reputable campaign member here will accept your offer unless your project is backed by VC or you have enough funds to cover  sufficient marketing expenses.

There are tons of bounty campaign on the altcoin section that disappear after distrubiting worthless token and wasting participants time and effort. I hope that your project is not same with them.