I would use steem bounty, but.

Steem bounty seems like an OK idea. There's just a few issues: 

1. The 20% community payout. That basically means someone like haejin can come along, post a nice little smiley face emoji on my post and walk off with 20% of my money – and that doesn't help me get better content. Even slightly. 
2. There's no list with all the bounties, so I'm unlikely to get any bounty hunters on my post. 
3. It makes no sense for bounty hunters, who may put in effort only to find that the not only the bounty creator can't write (trust me, even the creators of steem-bounty are unable to do so) – but they also don't want well-written content on their posts. 

To be honest, your scheme sucks. Seriously. 

Barely anyone gets good quality comments. And those that do don't give the writers the promised rewards, and just walk off with their free work. Also, they'll be introducing fees soon – and I'm tempted to set up a rival service with 0% fees to compete with them, and stop them from making money. 

@knirky, who were you kidding when you set this thing up?