If the user has opted to make their email public you can view it on their profile page. Other then that there is no way. We do not yet have private messaging tools on the forum module. That would be handy but we currently don't have them

I don't think there is a thread where people post if they want to be hired for work, but I am sure if you make a new post asking for help from people to build some new sites, and you are willing to pay, people will respond. I know I would