You might want to look into the DriveWorks add-in. A limited version, DriveWorksXpress, is available in SolidWorks and may do all that you need to do.
I would also consider using a master sketch or part in your assembly. Put the lengths and angles in that part and then propagate them to your parts using some suitable method, like Convert Entities.
I agree with Jerry. Sounds like a very good senerio for Driveworks.
As mentioned by Jerry, this sounds perfect for DriveWorks.
One of the great features of DriveWorks is that you can start with Xpress which is free and in every installation of SolidWorks. You can begin automating your procedure free of charge. If however you would like additional functionality that isnt available in Xpress your project information can be simply opened in DriveWorks Solo and you can continue working without any lost time. This is the same as if you were to go from DriveWorksXpress to DriveWorks Pro or DriveWorks Solo to DriveWorks Pro.
There is obviously a learning curve with understanding how DriveWorks operates. However this is typically quick as the rules that you create are based on the same syntax used by Microsoft Excel, so there is a strong probability that you will recognise a lot of the rules available to you.
If you would like to find out more, do take a look at our website - http://www.driveworks.co.uk/
Under the Xpress section you will find Sample Projects, Tutorials, How-to Videos and Webinars that you can sign up for.http://www.driveworks.co.uk/products/driveworksxpress/
If you do have any questions though, feel free to contact me or your SolidWorks Reseller.
Is this something that can be controlled with master sketches at thetop level? Sounds like it.