I have 15 years of experience in Linux server administration and PHP Programming.
I can upgrade phpBB 2 to version 3. But mods are different, so if we need any, we have to find mods for phpBB3 that do same function and install it. Any phpBB2 mods can't even. Even phpBB2 itself is not upgrading, what we do is install phpBB3, them import data from phpBB2.
Message me, let's discuss the project.