Are there really people out there that are "just" idea guys? I can't imagine they could get very far in life without picking up some other skills.
Often people consider the 'idea guy' to be the ceo, or marketing person, because that persons direct work is often not visible in the product itself.
However, if you think of the Steve Blank model of creating customers and defining products, isn't that a great fit for an idea person? Somebody who can have an idea, talk to potential customers, and figure out what the final product should REALLY be?