Receptional_Andy - 10:12 pm on Jun 8, 2008 (gmt 0)

Thanks for the clarification, rambatz.

Based on what you've said, I'd say the first task is to make sure that the 2 of the 4 you've chosen are the most effective ones. I would base this on revenue/profit and not number of searches (unless one converts much better than another for reasons that you can fix!).

It's possible to target several highly competitive keyphrases with a single page or single body of content, but it isn't easy and doesn't always work. You clearly already appreciate that your site needs consistency in order to work for users.

It might be worthwhile trying to figure out what the difference is between the audiences and why they tend to use different words to describe the product/service. This could give you some insight into a long term strategy, even if that involves making a different type of content to get as much coverage as possible. As you are already using and seem pretty well versed with PPC, I recommend playing with your PPC traffic to get some additional insight.

A pure SEO consideration is whether or not search engines are able to make the connection between the word variations. If they are, you're job is a whole lot easier :)