Forum Into Gallery, or Gallery into Forum

Hi, I need both a forum and a gallery. And I am thinking of phpBB2 and of course Gallery2. What is the best way to do this - to embed Gallery2 as a module in phpBB2, or to embed phpBB2 as a module in Gallery2? In other words, should the main application be the forum or the Gallery, and then just a link to the other application?

And for those of you who have done it, which forum is best when used together with Gallery2? And would it be very easy to integrate one into the other (for someone who knows absolutely nothing about software)?

Thanks.