I have also been thinking of creating a forum on my site. All of your comments are extremely helpful to me making a decision.
The ones I have been looking at are through WP. I found them under the plugins by searching 'forum'.
I don't know if your site is built on WP or not. If so, this would be a simple addition of plugin.
I agreed with you. I have too use these phpbb into my website. It simply you need something information about the programming. Its better to hire the developer.
If you want to make your forum successful then you need to collect a lot of information regarding to your forum topic such as rules, great ideas, Mature and Professional, add some fun topics, etc. After that you need to find good friends, very important to make sure everything works. You can use anyone default application for coding, Add some custom styles, Logo, etc, to your forum. Once complete your forum then you need to promote it. So their are several options for marketing to your forum website such as Advertising, Affiliating and Partnerships, Search Engine Optimization, etc.