Tricky Wordpress loop task

Here is what I'm needing done: I have a Wordpress website I'm developing with two different areas divided by categories. One category is 'Client' and the other category is 'Professional Blog'. I need to get the posts from the 'Professional Blog' category that have the tag of the client name (for example, all posts tagged as "Google"). Once I have those posts with the client tag name, I need to display those posts underneath the 'Client' post. Example: The 'Professional Blog' category has several posts with "Google" as a tag. I want all those posts tagged with "Google" to be displayed and listed underneath the Google client post. I should be able to accomplish this with a Wordpress loop and if/then PHP statement but I'm having trouble sorting it out. If the problem isn't clear, please let me know and I'll try to clarify or provide another example.