That looks good to me too :)

How about this : I told him that if he promised to be brave enough not to fear anything anymore, he would receive a special prize, which was eating at a restaurant of his choice.

These tenses are all OK. To my mind, your sentence is fine as it is. Of course, as Peter points out, it's often possible in English to write things in several different, equally correct ways.

Hi Saeiid, what do you want to say exactly in this sentence? You don't normally suggest someone would do something. You suggest someone 'should' do something (to give advice or recommendations). I also suggest re-structuring your sentence. I would put the -if clause (if he promised....) at the beginning of the sentence, this sounds more natural. Think about the main action and then the consequence of the action. I hope that helps and if you need more practice with your writing skills send me a message and we can organise a lesson.