Linking forum accounts to ecommerce accounts

[bcred]

Hi, I'm currently looking into forum alternatives for a major ecommerce site and, while I personally love vBulletin, am not sure whether it is capable of meeting the needs of this particular forum, so I have the following questions and any advice would be greatly appreciated.

All our forum accounts are linked directly to a users buying/selling account on the main page with our current provider. Is it possible to do this using vBulletin, whereby, for example, banning a user on one site or changing one password, could also be used to effect the other. I know this isn't possible 'out of the box', but roughly how difficult/expensive would it be to get this done.

How difficult is it to transfer old posts done on an entirely different piece of forum software only vbulletin... lots of them (this again i understand is more of a difficulty cost issue)

My question really is about whether these two things are possible. If they are, any insight into just how difficult they are to do.

Thanks in advance for any help,

Seth