Rapidly Growing Site, do we drupalize?

I've got a professional site that is growing by leaps and bounds. Primarily it consists of a large vbulletin forum. Secondary to this is a growing magazine section that currently uses Wordpress to get the job done. Third are several other scripts that aren't necessarily integrated although I will eventually have them share the same user account database.

I'm presented with the challenge of integrating a content management system that will allow me with different profiling on a going forward basis. Having such a large vbulletin forum with over 100,000 posts makes me think that switching to drupal forums is not a good idea, for seo and practically. I don't find the drupal forums that much fun to use or as simple to view content, although it's certainly functional.

The question really is in one of merging vBulletin and creating the other items I need around it, e.g. a business directory, a jobs database and resume upload, a resources directory (currently part of vBulletin), and an area for contributors to write articles. I don't know how many of you are using the script but, for me, my users won't be blogging too much although they may. Picture galleries and videos will probably not be a large part of my site. Being able to expand profiles for other user definable categories might be useful.

Here was the thought - vBulletin only provides limited user profiles and is only useful for forum activity. I can redirect users to their "Drupal Profile" which is the main one. I can have a link on every profile to view a users forum statistics as well as a link to VB from the drupal profile and that's fine.

The issue really is with regard to (1) integration of the two for seeding user name/passwords, (2) the way the two play together, and (3) if anyone has really been able to create a useful community environment with drupal without too much pain. Yes, it's powerful. The reason I stayed away is because many of the best projects here involved months of time an specialized programmers to get things done that seemed relatively simple and provided as more tweakable standard plugins with other packages. Additionally, the challenge of integration vbulletin this far and fun with designing templates also led me to use wordpress for the CMS portion for launch. It has served its purpose remarkably well thus far.

Thanks for all comments and opinions.