I have the same problem...users who wanted to immediately download a report to Excel and start doing their own analysis. They do not want to spend time removing headers and other stuff from the Excel spreadsheet.
I solve this by adding conditional statements to boxes, rows, and images that I don't want to export to Excel. Then I put an extra parameter in the report called 'Export to Excel'. When the user selects the Export to Excel = true, then the conditional statements hide those elements.
Basically, it's a way to trick SSRS into making two reports from one .rdl.
Here's my tutorial for this method (with screen shots). I hope this helps.
Hiding Parts of SSRS Reports from Excel exports
http://sqlstuff.weebly.com/report-server/hiding-headers-of-an-ssrs-report-from-excel-export