Why delete content; if you have old content that's an search engine goldmine for incoming traffic... I was absolutely hate to get rid of all of that especially if you run an online service like you do.
You could delete it, or you could mirror the db then prune the old posts off of the main forum and have a separate archive forum.
Just semi curious of the 1gb limit...
As Ruben stated, the prune tool would be the proper method of pruning old content, even if you hired someone to do it for you it'd be the same method.
