We have been promoting 2 sister sites that are very similar in nature. They offer similar services (marketing, SEO, etc.) and have a similar design and feel. Both of them currently have a PR of 3. It's getting to the point that they are competing with each other for ranking. We've decided to combine them into a single site in order to focus all our efforts into promoting one url.
Can anyone recommend the best way to do this? Should we create a delayed redirect, where they each say 'We've moved...' or should we just set up an immediate and permanent redirect? Is there any way to make sure the PR from both sites is carried over to the new one? I'd hate to lose all the backlinks we've done.
Any advice would be appreciated.