I have been slacking in checking out addons lately being that when I am at the computer now a days I am trying to write my own code. However, recently someone (two people actually) pointed me to look at Chris Deeming's media gallery addon and I would think that this would cover what you have described as what you are looking for in functionality.
I am sure there is a bunch of scripts out there and if I spent some time looking for one I am sure I could find a nice one, however if you plan on having it integrated into xenforo at a later time you will have either be a coder or hire one and I am also pretty sure that it will cost you more than it would to just get that above addon.
I searched this and pretty much all of the scripts that look decent cost more than the addon so I have a hard time looking for and recommending a script unless for some reason you really just want a standalone script.
Thanks to you both for your thoughts - I've actually used Coppermine in the past myself, and it's a very good gallery system, I'm just trying to figure out something that would have more "social" feeling and functionality into it. I've looked around in the past for Coppermine custom theme designers but didn't find anything.
Chris' gallery add-on is an interesting suggestion, I've already bought it for my main site but I'm waiting for user albums and importers before I can use it, but it might be worth a shot along with some customizations and/or stripped down version of the forums :mrgreen: