Search for 'Article Forums' on this site in the mods section, you could also try Vbadvanced Dynamics but idk, I've just had that purchased and the support is seemingly lousy and it's fairly buggy with the addition of the new editor to Vb 4.1.4.
The latter is a better option, the former is a safe and free option - But neither will fit your needs 100% - Sometimes you just have to make do with what you can or you could try custom coding it but I can't really help you there.
If your a confident guy you could look at how the article forums work and try and code your own system in a similar context.

Best of luck, hope this helps somewhat!