I suggest doing your research before installing any software.

By your own comments, you already know about vBulletin. It's not an overkill to purchase something that stands above all others.

Things you should consider:

• security
• community
• support
• ease-of-use for both you and your end-user
• available features / options (eg. expanded permission system, file system, etc)

How many posts do you expect it to have? Seems you forgot that useful statistic. I personally would not think vBulletin would be a bad choice for this situation though, but it depends on which of these wanted features are most important for you.

If it's security, vBulletin could easily be the top choice. And even if it isn't, this makes vBulletin worth considering. And should also say to you NOT to use phpBB for this. After quite a few exploits in the past and exploits found in software that integrates with it by default.

As for file hosting, I'd pick vBulletin or a more modern free board like SMF or MyBB. Because as far as I know, some older, commonly used free software does not support attachments at ALL. If you used vBulletin for this, you could also use a modification like a download manager mod with it.

Finally, if you don't want to modifiy raw coding, vBulletin would be better. PhpBB would be decent adequate if you didn't want to add mods. MyBB might be okay. SMF would probably not be so good in this respect, as I hear the source code has the style formatting mixed among it.

I'll show my support...

When I started my forum that I thought would be really small 20 months ago, I used e107.org. After a few months I outgrew that and moved to SMF 1.1. After a few months on that, I wanted a premium board so went with IPB. After another couple months I decided I wanted access to all the amazing mods here on VB.org so I bought vBulletin.

I'll save you all of the hassle -get vBulletin to start with and make your life a lot easier.