sorry to hear about what happened..
recently my 4images index was defaced due to an exploit in phpbb's old version. I can't believe people can do such damage in purpose. Especially to such a site. From what I hear it is a simple script that searched web for a certain versioned phpbb sites, and automatically run the script and damaged the sites. Thank god mine was only defaced.
I have never seen or heard this forum s/w before, I hope it works well and normally these types of forums are not always the target. If you were going to use paid svc vBB would have been a great choice, but good luck with this, and I surely hope in no time we can restore everything back to the way it was.
I am so mad that some of the great topics were lost.
Quick suggestion, the themes need to be worked on, the default is not so great to the eyes, and not too easy to read some times, the second one seems a little better with blue, but I suggest try to get one with smaller fonts and more organized view.
Good luck to everyone and let's get to work now.