Assuming you don't have an IR the 'some cumulus' part in your post is important. As long as you are in sight of the ground you can be vfr on top of anything so 'some cumulus' wouldn't be a problem as long as you maintain your minimum distances from cloud.
Edit: I think your 'vfr on top rating' may refer to an 'IR lite' rating that EASA are proposing to introduce. It will allow you to be vfr on top of solid cloud cover as long as your destination airfield is vfr. Personally it sounds like an undertaker's dream to me but my opinions aren't based on much other than common sense, so they will obviously differ from EASA.
Last edited by thing; 20th Jul 2013 at 14:48.