Joomla Virtumart Category Page Tweak

I want to add text/images above the sub categories on the new category page. I think I'm using the correct Category Browse Page and flypage but the changes are'nt showing. It may be that the cache needs cleaning but am worried that if I do that the SEF urls will change (from previous page title changes) and I'll lose google rankings.
Hopefully theres a way to get this working without any SEO issues - help and advice would be appreciated so I can view the category as I wish.